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Tim JA
Tim JA, HVAC Technician
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I have an ecoTEC plus VU 606/5-5 (H-GB) 64 Kw boiler running

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Hello, I have an ecoTEC plus VU 606/5-5 (H-GB) 64 Kw boiler running my Central Heating, Hot water and Underfloor heating controlled by Honeywell Evohome wireless control system. A couple of things. 1) The boiler seems to fire up for short (1 min) periods at all hours even when there is apparently no heat demand (I have turned off all heating circuits and hot water is timed) so almost every night at 11.45 for instance. Its pump runs but the main C/H one does not. and 2) The boiler is very noisy and the whining/droning noise it makes transmits through the main wall of the house from the basement when it fires up - is this a fault? Should it make the whining noise? Is there a way to isolate it from the wall? It is a real problem. Thanks.
JA: How old is your Honeywell boiler? What water pressure does the gauge show?
Customer: Water pressure is fine - I keep it topped up. Boiler has been in for year (you just wrote about its first service being due).
JA: How long has this been going on with your Honeywell boiler? What have you tried so far?
Customer: All the time we've had it and I'm not sure what to try now - we've tried most things in control terms.
JA: Anything else we should know to help you best?
Customer: When its doing one of its random firings the display shows a flashing radiator symbol and when stopped thew symbol is solid and an egg timer is flashing.

Good morning, welcome to the Technical section in JustAnswer; my name is ***** ***** I will help you today.

It sounds like the installer has not configured the boiler to use an external heat demand. Do you have a room thermostat?
_____

If you receive a phone call offer, please ignore it - these are system generated and outside my control. My understanding is that you won't be charged if there's no phone call.

Customer: replied 1 year ago.
Hello Tim, I think so as it uses a Honeywell Evohome System and when it is switched on and calling for heat the boiler fires. Would ALL heat requests go through to one place to be sent to the boiler?
Customer: replied 1 year ago.
Hello Tim, I think so as it uses a Honeywell Evohome System and when it is switched on and calling for heat the boiler fires. Would ALL heat requests go through to one place to be sent to the boiler?
We have 4 thermostats for U/F , 6 radiator stats and a separate stat for towel rails.

OK. It's certainly relevant that you have UFH, because that potentially requires an extra connection to a wiring centre.

The conventional configuration for a heating system like yours is for the heat demand from all zones to converge electrically at a wiring centre, and the demand from a hot water storage vessel (if you have one), and the demand from the UFH system.

Your radiators thermostats - are they wireless, or simply acting locally on the valve tp open/close it?

Customer: replied 1 year ago.
As far as I know all of what you say is the case - there is a Boiler Control and Hot Water control junction box which receive wired signals from the Heating/Hotwater/Towel Rail Receivers (they get their instructions wirelessly from the Evohome controller which co-ordinated the various measuring devices (stats, trvs) around the house. All stats are wireless, TRVs control local radiator and signal boiler to fire on demand as do room stats for the U/F.
Customer: replied 1 year ago.
As far as I know all of what you say is the case - there is a Boiler Control and Hot Water control junction box which receive wired signals from the Heating/Hotwater/Towel Rail Receivers (they get their instructions wirelessly from the Evohome controller which co-ordinated the various measuring devices (stats, trvs) around the house. All stats are wireless, TRVs control local radiator and signal boiler to fire on demand as do room stats for the U/F. Are you also able to suggest why the boiler makes so much noise?

Regarding the noise, without wishing to be a doom-monger, sometimes these noises can't be solved. I have one customer whose Vaillant boiler had everything single part replaced, except for the casing, over a period of 18 months, because it was making a droning noise. In the end Vaillant gave up and replaced the boiler as a unit, which didn't make the noise. Nobody (outside Vaillant) will ever know the cause.

Did the noise start within the warranty period?

Customer: replied 1 year ago.
The boiler has made the noise since it was installed just over a yr ago - it's never been quiet and I've got emails to my plumbing guy going back - what would you suggest I do to deal with it?

Is your plumbing guy the person who installed the boiler?
_____

Going back to your original problem, which isn't solved, do you want guidance with that?

Customer: replied 1 year ago.
he is and I've got him and the electrician coming on Friday but it doesn't feel like a control issue as I've tried with all the Honeywell controls off. Could be a fault and Vaillant say the display on the boiler (flashing radiator symbol) indicates it is receiving a heat request but none of the receivers is active when the boiler is doing it's thing so no idea how that works....

OK. What your describing is a control issue. It might not be a problem with one of your thermostats, but you can't eliminate anything until the fault is found and fixed.

This is the kind of problem that I solve day in day out. As I said at the beginning, if the installer didn't configure the boiler to use an external thermostat then it will default to the behaviour that you're describing. I correct at least one of these a month during the winter season. But you have an electrician coming on Friday so between the two of them I would hope they can get it right.

Customer: replied 1 year ago.
Could you elaborate a bit more on what you mean by "configure the boiler to use an external thermostat" please? How would he check that on my particular boiler? Thanks

The electrician won't know, unless he happens to be Gas Safe registered too, but a decent heating engineer should know, and Gas Safe engineer who doesn't know should get themselves the appropriate Vaillant training.

This is one of the most sophisticated domestic boilers on the market, with a plethora of test modes and configuration parameters. The installer needs to follow the manufacturer's detailed installation instructions - there's no quick summary that I can give you. If I could, I would.

The electrician won't know, unless he happens to be Gas Safe registered too, but a decent heating engineer should know, and Gas Safe engineer who doesn't know should get themselves the appropriate Vaillant training.

This is one of the most sophisticated domestic boilers on the market, with a plethora of test modes and configuration parameters. The installer needs to follow the manufacturer's detailed installation instructions - there's no quick summary that I can give you. If I could, I would.

On top of that, you have a complex installation with multiple zones, and UFH. It's not an installation I would necessarily expect to get right myself, first time, so I would test extensively before handing over to the customer.

Customer: replied 1 year ago.
Thanks for this Tim - I have passed our conversation on to the plumber and electrician in prep for their visit on Friday afternoon.
Could you answer a possibly related question also please?
The U/F heating is run by 2 Honeywell Home U/F heating controllers controlling 2 U/F manifolds fed by a 28mm pipe from the boiler. There is a Zone Valve on that circuit which the plumber had latched open on the basis that the manifold mixers and individual heating circuit valves adequately shut off the flow from the boiler (assuming that if they were closed then if the C/H pump was running for either hot water of to feed the upstairs TRV rads it would be pushing against closed valves so the hot water wouldn't circulate to there).
My observations are that the water does circulate and heats the large feed circuit and any rooms in between like the cellar - the flow and return on that circuit are hot even when there is no u/f heating demand. I presume that the mixers are designed like that so any hot water they don't need for the underfloor circuits simply returns to the boiler? In that case, it would seem the zone valve IS required otherwise there is quite a waste of heat? Thanks

The MZV that has been latched open must also have been disabled electrically, unless it’s faulty. The purpose of the MZV is two-fold:

1. To prevent heat circulation into the UFH zones when there’s no demand. As you say, this reduces wasted energy.

2. To provide an electrically independent (of other zones) heating demand to the boiler.

The reason you were given for latching it open seems fallacious to me.

Tim JA and other HVAC Specialists are ready to help you
Customer: replied 1 year ago.
Hello Tim, I have had my plumber and an electrician here today to try to get to the bottom of the issues and we have hopefully a Vaillant Engineer my plumber knows coming on Monday to check the configuration of the boiler. I need your further advice on the Zone Valve issue. You are right that the U/F ZV is not connected and was latched open on the instructions of someone from Honeywell (Residio) Technical after there was a problem with the U/F manifolds not receiving water (I think because maybe the ZV was not being told to open). He told us that there was no need for a ZV because the individual U/F valve heads effectively cut off the water flow and therefore presented that circuit with a "dead end" so water would not flow very far up it. This does not appear to be the case as I think the manifolds have a by-pass so when all heads are closed they still get a hot water feed. In that case we need a zone valve to cut it off don't we? I wonder if you have any experience of Evohome U/F controls and can comment? I don't see why, if the U/F controller turns on the boiler and C/H pump why it cannot also open the U/F circuit ZV? Seemingly thats what the separate Hot Water, Piped heating and Towel Rail controllers do? I am asking the same question of Honeywell's support people but they have not been terribly good at solving my issues up to now so I am hoping you or a colleague may have an insight to offer. Many thanks.

Thanks for your rating :-)

Answering your questions one at a time...

Q: ...we have hopefully a Vaillant Engineer my plumber knows coming on Monday to check the configuration of the boiler.
A: I'm relieved to hear that!

Q: I need your further advice on the Zone Valve issue. You are right that the U/F ZV is not connected and was latched open on the instructions of someone from Honeywell (Residio) Technical after there was a problem with the U/F manifolds not receiving water (I think because maybe the ZV was not being told to open). He told us that there was no need for a ZV because the individual U/F valve heads effectively cut off the water flow and therefore presented that circuit with a "dead end" so water would not flow very far up it. This does not appear to be the case as I think the manifolds have a by-pass so when all heads are closed they still get a hot water feed. In that case we need a zone valve to cut it off don't we?
A: Yes, quite so. If you have a bypass downstream of the MZV then there would be insufficient control of heat flow to meet the current Building Regulations.

Q: I wonder if you have any experience of Evohome U/F controls and can comment?|
A: Yes I do , so yes I can comment.

Q: I don't see why, if the U/F controller turns on the boiler and C/H pump why it cannot also open the U/F circuit ZV?
A: Firstly, I would prefer to say that the controller "presents a heating demand", not that it "turns on" things like the boiler and/or pump. owint to the boiler's pump overrun function, and the potential presence of a MZV, the controller might fail to turn on the boiler through no fault of its own. I know it sounds pedantic, but sometimes the wrong wording can lead analysis in the wrong direction.

Q: Seemingly that's what the separate Hot Water, Piped heating and Towel Rail controllers do? I am asking the same question of Honeywell's support people but they have not been terribly good at solving my issues up to now so I am hoping you or a colleague may have an insight to offer.
A: My answer to that is the Honeywell has not been paid to take a look at the big picture with your system, so they will probably revert to script and make the standard assumptions. Your system is quite complex, and not many people will be prepared to think about it without attending.

Customer: replied 1 year ago.
Thanks Tim but in terms of the last issue I’m still unclear as to how (and if) the ZV labelled U/F heating should be incorporated into the control system. The Honeywell Resideo people had said something about the u/f controller being unable to activate boiler pump AND ZV at the same time which is obviously necessary for the system to operate as it should. Could the secondary circuit in the ZV perform the function of activating the boiler and pump when U/F heat is called for with the Evohome switching the valve? I confess to not fully understanding how at present the boiler is called for when there is an U/F demand because there is not a U/F “receiver” that I can find wired to the boiler (there are 3 for Hot Water, Heating and Towel Rails which ARE hardwired to the boiler control junction box) so I can only assume the u/f controller utilises one of these to effect its activations? Presumably the solution might need to be that a separate Wireless Receiver needs installing to do the U/F boiler/pump/ZV switching? (Again I’m sketchy on the sequence and direction of control - Sensor, Evohome Controller, U/F controller, (Receiver?), boiler/pump/ZV maybe?). Would it be worth my sending a hand drawn schematic I have done of my understanding of the system or have you “got it”? Do you think someone should look again at the set up ?
This takes us back to the beginning, where I wrote “ The conventional configuration for a heating system like yours is for the heat demand from all zones to converge electrically at a wiring centre, and the demand from a hot water storage vessel (if you have one), and the demand from the UFH system.”I thought the purpose of your two contractors visiting together was to move forward with (a) working the system in a way that gives you control, and (b) configuring the boiler to match that system configuration. It seems that they have recommended a Vaillant engineer do the (b) task, so who is doing (a)?
Customer: replied 1 year ago.
Problem is they do not understand the operation of the Evohome system Fully so the questions I’m asking you are those which were raised during their visit and to which they didn’t have a proper answer - namely was Evohome tech correct in saying don’t use ZV and if not what is the proper (actually any) way of introducing the required control of the u/f system under the present setup. There is a wiring centre next to the boiler (2 actually) but as I said it’s unclear how the u/f controller connects to it - how ideally in your view should it be set up? Sorry if we appear to be going round in circles - if I knew more about how the Evohome worked at the sharp end and how ZVs interface with the boiler/pump I might be able to draw conclusions but as I said unsure of the chain of control as I said in the last part of my note. There is no obvious Evohome installer here that I would trust (there’s one listed but I’ve not heard good things hence trying to fault find myself). Appreciate you patience by the way.

This isn't necessarily an Evohome issue; as I've said, each zone should present its heating demand to the wiring centre, and from there you should have one connection to the boiler. The conventional way to electrically isolate each zone, and to save energy, is to use a MZV for each zone. (There is an exception in single zone systems where a 3-port MZV can be used effectively.) There are other ways to achieve these two goals, but most people find those ways to be more complicated and more expensive.

You need one person to take charge of determining the best means in your system to achieve these two goals. So far, you've had two engineers attend, and taken advice from Honeywell, and from me, but nobody is actually achieving anything. I strongly suspect the Vaillant engineer will focus solely on the boiler. I don't want to sound like I'm scolding, because that isn't my intent, but you need someone to do what the original installer should have done, which is to integrate all of your zones, wire things up correctly, test the arse off everything to make sure it works, and then (and only then) hand over to you with an explanation of how it works. If that person does anything unconventional with the wiring or control methods, then it needs documenting prior to that handover. That's what any good professional would do.

I'm not saying that you can't DIY, but you have an uphill struggle in terms not yet knowing what you need to know, how much you don't know, and learning a lot very quickly. On top of that your system is about as complex as a domestic system can get without it being a small-scale industrial installation.
____

I'll do my best again to answer your specific questions...

Q: was Evohome tech correct in saying don’t use ZV and if not what is the proper (actually any) way of introducing the required control of the u/f system under the present setup.
A: I doubt it, but please recap concisely what the Evohome proposal was.

Q: There is a wiring centre next to the boiler (2 actually) but as I said it’s unclear how the u/f controller connects to it - how ideally in your view should it be set up?
A: So far I've seen no reason not to do things conventionally.

Q: There is no obvious Evohome installer here that I would trust...
A: Whereabouts in the UK are you?

Customer: replied 1 year ago.
I absolutely agree that there needs to be a "lead" but that has proved difficult since by circumstance the guy who installed the boiler and heating (not the U/F which was done by a specialist company who were not asked to supply controls only manifolds and circuit heads) was not trained in Evohome equipment but the supplier (RGB) apparently said the installation guide was quite clear so it shouldn't be a problem. Mistake or not its where I find myself. I therefore need to amass enough basic understanding for that person to be me. I'm gradually getting there but need some more basic questions answered I think.
I can see that what you say is correct - whilst it is a "complex" system, it conforms to the basic principals - 4 distinct heating requirements H/W, U/F, Traditional TRV'd radiators and a Towel Rail circuit. It looks like 3 of them are OK with perhaps a little tweaking of bindings.
The U/F element is where I just need a bit more basic info (I've asked Residio but not heard yet so if you know the answers - great).
Specifically I need to know how the Underfloor Controller(s), once notified of a demand request from the Room Stats transmit that request to the Wiring Centre (I'll find out from the electrician who did the install what he did to pass on the demand requests to the boiler/pump etc). It seems from the instructions like it (they at the moment) is hard wired to the boiler room and so probably fulfils the requirement for one connection to the boiler and circulating pump. Is that correct? And "traditionally" the wiring centre would therefore separately latch open the appropriate ZV for the circuit making the demand?
I do not at present know exactly what Evohome said to the electrician (he's injured so couldn't come yesterday) but I do know that the u/f ZV had been connected and was disconnected and latched open. I will try to ascertain exactly what was said.
I live in Torquay, Devon (you're not nearby by any chance? ��). As you say Vaillant wont be interested but hopefully the other (noise and phantom running) issues should be addressed by the guy hopefully coming on Monday. I am again chasing Residio for a response.... Thanks Tim

Erratum: "(a) working the system" in my previous post should have been "(a) wiring the system".

Unfortunately I'm not close to Torquay; I would have enjoyed knocking your system into shape!

In principle I'm happy to guide you and to keep answering your questions. I don't like being mercenary, but the reality is that I have to earn a living and I'm not being paid much for this topic. What would you think of the idea that you have a one month subscription? Then I believe you can keep asking new questions for no extra fee (but please check my facts on that). That way you have access to a resource (me) and I also get something out of it. You can direct a question to me specifically and the system will prevent other experts leaping in to answer.

Customer: replied 1 year ago.
I'm happy to do that once I've heard back from the plumber and Electrician who I've just sent a missive outlining what you've said in terms of treating it ”conventionally”. Certainly the sparky will be back to me quickly so I should know in a day or so - I need to call Resideo again the chase them about wiring of the u/f controllers - back to you as soon as I'm a bit clearer on Monday or Tuesday - thanks

That sounds like a good plan - I should have suggested waiting until after Monday, which was my intention.

A thought has circled back to me from Saturday - I wanted to mention OpenTherm, but in one of my posts I asked what Honeywell were proposing and was waiting to see if they had mentioned it.

It’s possible that somehow has attempted to use the OpenTherm interface to control the boiler from the Evohome UFH controller. IMHO that would be problematic, because implementations can differ between manufacturers, so it’s not reliable. It will be interesting to hear what the Vaillant engineer finds.

Customer: replied 1 year ago.
I spoke to my electrician who hadn't been able to attend last week due to injury and he said that a Honeywell technician on the tradesman tech line had instructed him not to use a zone valve - the reason was a bit vague (it doesn't need it or won't work) and the Residio consumer helpline person cannot advance anything else in terms of the "design of the system" which is weird given it seems their other techs offer such advice unbidden.... I will update as soon as I hear from Vaillant about the other stuff but if you happen to know any other advisers with experience of this kit maybe you could ask if you've got a quiet moment. Cheers ***** *****

I really don't think this is a question of asking different people or companies what needs doing - you'll get one opinion for each person you ask. You just need to follow the Evohome installation instructions.

Which Evohome products do you actually have?

Do you have the HCE80, and/or the R8810?

If you're going to do the installation, the following online course will help you:

http://youlearn.honeywelluk.com/index.php

Er, that was the wrong page. Try this one:

https://youlearn.honeywelluk.com/course/evohome

Customer: replied 1 year ago.
Hi Tim, found out why the zone valve was counter indicated. There are 2 u/f manifolds each with a pump so my electrician was told that if the zone valve was connected then when 1 manifold powered the zone valve when the pump was activated, the 240v signal doing this would also activate the pump in the other manifold (as it's a parallel connection) and since all control heads would be closed the pump would be pushing against a dead end and could burn out. I need to check if the manifold has a bypass (provably not) and also if this is a genuine problem. I've read the training course but it specifically fails to address this issue as you'd expect. Looking at options to include 2 zone valves in the u/f circuit.

OK. I understand the reason given, but I disagree with that person's logic.

If the concept of treating the UFH system as providing a heat demand is upheld, then the problem melts away. What you've ended up with is a bad design that has been half-implemented.

It's conventional for the UFH controller to power the pump on the manifold, not for the MZV external to the manifold to do it. The MZV simply opens the flow to it's "zone", and when open it presents the electrically decoupled heating demand to the boiler.

If someone wanted to use the MZV to power the UFH pump, for whatever bizarre design they had in mind, then they should have installed one MZV per UFH manifold, which is an option that's still open to you. However, the simply solution is to disconnect the MZV orange wire from the UFH pump, and connect it to the same terminal as the other orange wires from the other MZVs. And to use the UFH controller in the way that all other UFH controllers are used.

Do you have just one UFH controller for both of the manifolds?

Customer: replied 1 year ago.
There are 2 U/F controllers but there don't need to be as the Merchant didn't work out that heating loops would be combined into zones so we've got 2 controllers capable of running 13 zones and we actually use 4 zones (Lounge, Kitchen/Dining, Entrance Hall and Study) so we could combine into one but of course still have 2 manifolds.
What the electrician is saying is that Yes the U/F controller powers the pump on either of the 2 manifolds (and presumably the main C/H circulating pump and boiler) - and as it's set up at the moment that's all it does as there is no MZV because it's disconnected BUT if we re-connect the MZV and wire the U/F controller to power it at the same time as the manifold pump etc then because there are TWO manifold pumps, the 240v signal which powers the MZV open feeds back and in effect powers the other manifold pump even though IT'S sensors are not calling for heat so running the risk of it pumping against a dead end and being damaged eventually. Am I making sense? Does your orange wire solution stop this feedback from forcing both manifold pumps to run when either are powered by the u/f controller (because they are electrically linked?).
Customer: replied 1 year ago.
There are 2 U/F controllers but there don't need to be as the Merchant didn't work out that heating loops would be combined into zones so we've got 2 controllers capable of running 13 zones and we actually use 4 zones (Lounge, Kitchen/Dining, Entrance Hall and Study) so we could combine into one but of course still have 2 manifolds.
What the electrician is saying is that Yes the U/F controller powers the pump on either of the 2 manifolds (and presumably the main C/H circulating pump and boiler) - and as it's set up at the moment that's all it does as there is no MZV because it's disconnected BUT if we re-connect the MZV and wire the U/F controller to power it at the same time as the manifold pump etc then because there are TWO manifold pumps, the 240v signal which powers the MZV open feeds back and in effect powers the other manifold pump even though IT'S sensors are not calling for heat so running the risk of it pumping against a dead end and being damaged eventually. Am I making sense? Does your orange wire solution stop this feedback from forcing both manifold pumps to run when either are powered by the u/f controller (because they are electrically linked?).
I think we have 2 HCE80s

Nearly. I'd like to get you to stop thinking about pumps. It's leading your thinking in the wrong direction.

Conceptually, the UFH manifold and everything on it, including the pump, is one component. The UFH controller is part of that component, and manages the pump, the actuators for the loop valves, and accepts inputs from the roomstats in the UFH zones. Whether or not the UFH pump runs should be down to the relevant UFH controller.

You're probably about to ask id the UFH pump should run when the zone valve for that manifold is closed, and why would it. The answer is yes, and the reason is because it's designed to do that. The UFH pump is there to circulate water within the UFH loops. That's all. Nothing else. When all of the UFH zone room thermostats are satisfied, the controller should then turn off the UFH pump. If it wants to. That it's business. It doesn't matter.

Separate to all of that, the UFH controller is capable of presenting a call for heat from a heat source. The UFH controller doesn't know or care what that heat source is, or whether or not there's a pump - that's none of its business.

Again, this basic design concept has been chopped up into bits and then badly implemented in your system.

So, the call for heat from any UFH controller should be treated exactly the same as any call for heat from any conventional room thermostat. It doesn't matter how many calls you have, or where the calls come from. The call from the UFH controller should power open the respective MZV. The switched live from the MZV is the final stage in the process of presenting a heating demand to the boiler. Again, it doesn't matter how many potential demands there are from MZVs, or indeed where they actually come from - the boiler neither knows nor cares.

Does this make sense?

Customer: replied 1 year ago.
Tim, I am frustrated as I suspect are you. I absolutely get the idea that the U/F manifold/pump assembly is one component just like a trv and that the control of it should be solely the function of the U/F controller. The problem is that my electrician was told by Honeywell specifically not to include a ZV because it would feed 240v to the other manifold pump and turn it on as well. He seems to think that is what was happening but I intend to test this as I, like you, find it amazing that this could happen and that Honeywell cant offer a solution. I'm not sure that short of you actually seeing the system there is more you can do if Honeywell cant offer any guidance to us. The idea that a MZV can screw up a system like this is beyond me and I'm sort of at a loss now....

I’m not feeling frustration at all, but I’m sympathetic to yours.

I don’t trust what your electrician is reporting. Honeywell’s answer depends on the question he posed, and if he doesn’t under stand underfloor heating then he could easily have posed the wrong question, or wrongly described the system, or led their thinking.

I’ll remind myself of the controller wiring at lunchtime, and I should be able to tell you exactly what should connected to what.

Customer: replied 1 year ago.
Hi Tim,
I was awaiting your response following your note above - I'm paid up for a further month by the way. My electrician was definitely told that the Evohome U/F controller system is not designed to work with a manifold with a zone valve "in front of it" - but that is crazy. Also we can't work out (schematics are rubbish in the Evohome installation instructions) how the U/F controller actually signals its instructions - whether there is an auxiliary switched supply to actually activate a zone valve if we want. Latest plan is for 2 zone valves - one for each manifold. I don't know if that necessary. Again any help or guidance welcome.

Morning!

I'm probably going to backtrack here, because with new understanding (since my previous post) I can actually see that a MZV isn't essential. As you say, the Honeywell schematics are lamentable, but before I get too far into that, and the backtracking, could I ask you the following?

1. What is the model number of the room sensors (aka room thermostats) that you have?

2. Do you have one room sensor per UFH zone?

3. What is the model number of the wireless receiver?

(Please note that I'll be out for a chunk of today, but will check in here when I get back.)

Customer: replied 1 year ago.
Stats are DT92E and there is one for each zone of u/f heat requirement so 4. U/F heating controller HCE80(R).
Customer: replied 1 year ago.
Trouble is there is approx 30m of 28mm copper in the manifold feed circuit which flows even when all u/f loops are shut so heating up my cellar etc which I do not want.
Customer: replied 1 year ago.
Hi Tim, Have you been able to make any progress on this? Cheers

Good evening, I’ve been out for most of the last two days, so I haven’t. I’ll be at my desk tomorrow morning if you could wait until then.

I can’t see an answer to Q3 - the wireless receiver. Do you have one?

Customer: replied 1 year ago.
Wireless Receivers BDR91 (3 of them plus 1 wireless Hot Water tank temp sender)

OK. I imagine that you one per HCE80, plus one for the Evohome hub. Assuming (which is always risky) that the switched lives from the BDR91s all converge at the wiring centre, and between them all present the heating demand to the boiler, then that makes sense.

However, you still have the original symptom of the boiler cycling on and off with no apparent demand, which brings me back to the boiler configuration.

This is probably a good time to draw a schematic of your system, to show what's connected to what.

Customer: replied 1 year ago.
No - the U/F controllers are their own equivalent- each is hard wired to the wiring centre and originally activated the zone valve as well as the boiler and main pump (as well as the relevant manifold pump). That I am told was the problem because they were parallel linked and somehow when one activated the zone valve it activated the pump in the other manifold which would be pushing against closed U/F loops and potentially burn out. I am yet to get an adequate explanation from Honeywell tech how that could happen if it is the HE80 which does the activation of the manifold pump which is wired into it. You could try them to see if close cross examination by someone who knows what they’re talking about might yield? 0300(###) ###-####and select installer. Worth a try if you’re allowed? Oh the other BDR91s are 1 for Hot Water 1 for Heating (that’s wireless rev controlled rads) and towel rails which have a stat always set very high so they are effectively just time controlled. The boiler has been reset by a Vaillant tech guy and now doesn’t cycle during the night (all heating is off via the Evohome controller). The HE80s are turned off also but when they are turned back on, after they have reset and fired the boiler (testing ?) and are in standby, one of them activates both zones and the pump for a minute at a time as before - not seemingly long enough to fire the boiler or the main c/h pump but I’ve not properly tested that part. Obviously no call from any stats. Confused
Customer: replied 1 year ago.
I meant wireless trv controlled rads.
Customer: replied 1 year ago.
Manual
https://ensupport.getconnected.honeywellhome.com/servlet/fileField?entityId=ka12G000000D6NaQAK&field=File_1__Body__s
Customer: replied 1 year ago.
Hello - I've not heard anything for quite a while - can you update me please with your thoughts on what I can do? Thanks Tim

Hello, to recap the problems...

1) The boiler was firing too often;
2) The boiler was very noisy;
3) The system configuration is undocumented and might be wrong.

I believe that (1) has been fixed. I'm not sure about (2) - is that still an issue? Regarding (3), I have a hunch that the HCE80s and BDR91s between them aren't connected and/or paired correctly, but I don't think we can do any more without a schematic diagram that shows what's connected to what. Then I can look at that and tell you if I think something needs correcting.

Customer: replied 1 year ago.
Hi - yes 1) seems to be fixed so no random boiler firing (software as you thought ) 2) Is not but that seems to be a mounting issue so will require some experimentation. 3) When you say schematic do you mean a wiring diagram? Ive not got one but I have done a block diagram of how I think everything connects but it's not clear to me how the boiler/pump is switched (the 3 receivers and the 2 u/f controllers are hard wired to the boiler room and the 2 working zone valves). Tell me what you need and I'll try but can you find out from Residio Installer tech line how it should be wired? I can't find a useable wiring schematic anywhere in their literature not could my electrician. Not great. Did you talk to them already? Would my block diagram help in that respect?
Thanks.

Yes - a block diagram would be spiffing. Even an incomplete one, as long as it's clear what's certain and what's uncertain.

To re-iterate: I don't need to know how it ought to be wired. What's missing is how it is actually wired.

Customer: replied 1 year ago.
Hi Tim - here is my take on the setup - I've highlighted in yellow the Wireless connections - everything else is hard wired - there are 2 wiring boxes (water and heating) near the boiler where I'm guessing all the signals converge. What I do not know under the Evohome system is how the receivers physically effect the required switching - the BDR91s are easy I think - its the U/F controllers I'm not sure of - I do know that the wiring from them to the bolier room is paralleled. Have a look and tell me what else you need eh?
Thanks

Acknowledged. I'm probably going to struggle to find time to look over it until later tomorrow afternoon, but if you don't hear from me before Thursday morning then by all means give me a prod.

Customer: replied 1 year ago.
Hello Tim, Have you managed to look at the problem again?

Good afternoon!

I hadn't, so thank you for the prod. I will look this afternoon.

Customer: replied 1 year ago.
Thanks - did you try speaking to the Resideo Installer Tech line by any chance? I can give you the number etc...

I've spoken to them in the past, but not very recently. They were helpful enough, as far as I recall.

I have printed out your schematic so that I make notes on it, so will get back to you ASAP.