Appliance Repair Questions? Ask a Technician for Answers ASAP
Hi, my name is ***** ***** I have been in the home improvement and repair field for 20 years. I will be very glad to help you today. Do you have a wireless thermostat?
The error is indicating your controller is not communicating with the transmitter. If you bring the thermostat control closer to the transmitter and replace the batteries with new batteries that should get it communicating again. Once it is communicating that will sort it. When the batteries get a little older and you have a fair distance between the transmitter and receiver it will lose it's signal. Replacing batteries with fresh batteries and re-establishing the signal will sort it.
Hi Mike, I'll give that a try and let you know. Give me 30mins or so as just on another job. Ta Dan
Hi Mike, have taken a look at the thermostat and it's mains powered so I can't take it off the wall, it's probably only 2ft from the boiler. Can't see any way to test whether it's working or not... can take a pick of it if that would help?
Are any of the communication wires on the control loose?
There should be a model number on the front of the controller if you're unsure if it is wireless or not. You could send the model number to me and I'll be able to tell you more. The issue us certainly the controller and the repair has much to do with the type.
Hi Mike, started replying earlier and then had the same thought so I've just been trying to validate the thermostat model. It is a Siemens RAA20-GB, here's a link to the installation manual (http://w3.siemens.co.uk/buildingtechnologies/uk/en/building-automation/residential-controls/documentation/Documents/raa20_d.pdf), not very informative but I've not been able to find any troubleshooting info yet. As far as I can tell there is no issue with the power to the unit, but I'm not 100% sure how it's linked to the boiler. There doesn't appear to the a power ring or anything?
There is the possibility that turning the power off and then on will reset it. If that does not reset the controller then looking to see if there is a loose communication wire would be next. The controller is wired directly to the unit. If you remove the face plate then there is a screw that holds the mounting plate to the wall. Possibly just one of the connections has come loose.
Upon inspection you may also find evidence of a scorched wire connection and that would indicate there was a power surge while you were away. This happens from time to time also and when it does it ruins the controller and it would have to be replaced.
There may not be evidence of a power surge at all. If you have a multi-meter and you are familiar with checking voltages you could check the voltages on the wires for the controller also.
Usually they have a battery backup also but I did not see that in the manual. When you remove the face plate and if there is a battery then that may be all that needs to happen is replacing the battery. The units without a display are a little more difficult to assess since there is not an indicator on it to display exactly what is the issue. No worries if you cannot check voltages etc. Basically if there is not a battery and there is not a loose wire then replacing the controller is the fix.
The replacement comes with very detailed directions for installation and if you are a bit handy it is certainly a DIY project.
Hi Mike, yep, had already removed the faceplate, deff no battery back-up or loose wires, have checked voltage and there is power. Am just about to take the front of the boiler off to just re-check the wires into that. Is the usual set-up for a thermostat like that to be wired into the power supply for the boiler itself? While I can't trace the wires fully that's what I've assumed from what I can see...
No point in checking the voltages at the boiler since the voltage is there at the controller. The only other possible fix without replacement at this point is turning the power off for about ten minutes and see if it resets.
You can test by linking terminals 3 and 4 on the boiler input strip if the boiler fires then it proves the boiler is OK. They are at the bottom of the boiler just follow the main incoming cable and you will see it.
There should be a wiring diagram in your manual also.
Here is the manual if you do not have it with wiring diagrams on the last pages.
I will be stepping away for a bit. Time to call my Mum. I will be back if you have any further inquiries. Mike
Just been looking at the manual and the wiring diagram, but still not 100% sure what I need to do, just going to look at it on the boiler to see if that's clearer...
Very good. I imagine by the time you have more questions I will be back from my phone call about the same time.
if you've not got on the phone yet can I just confirm that the terminals go up to 9 and has live etc on as well?
funnily enough sunday is the day I catch up with my mum too, was on the phone to her when your initial response came back...
just had a look, so if terminals 3 & 4 are the ones on the block that goes to 9 that's cool, but whats the best way to link them? the manual says "For test purposes, disconnect external controls from terminal 3 - 4 and replace with a bridge between these terminals. It appliance then operates, the fault is with the external controls."
How do I do that? sure it's obvious but I don't want to go tampering with wires..
You should have 230v across 4 and 5.
just going to step away while you're on the phone, be back on in 20mins
Yes so linking the 3 and 4 would be done by bridging a wire between the two
Going to the phone now.
Hey Mike, so to bridge do I just connect the two with a standard copper wire? on the board there is a grey wire going into 3, black into 4 and blue into 5. Do I need to take any wires out at all?
If you bridge 3 & 4 that would be the same as the control calling for heat. Yes just bridge with wire.
yep, that did the job... it fired when I bridged and stopped as soon as I took the wire away...
so that's the thermostat then
Problem solved. As suspected the control is failed.
just looking at replacements, you mentioned earlier that getting a digital one might be a better option as it's easier to tell if there's an issue... I figure that the best option is to go for siemens again as it should be similar installation, but go for digital and programmable
will try and take it on as a job... hopefully shouldn't be too complicated... although don't be surprised if I'm back again... :)
thanks for all your help, will rate now too. enjoy the rest of your sunday... Dan
That will offer the most options. It all depends on your preferences. I have a programmable and we hardly ever program it. We still use it like it is not programmable and adjust it when we like. The digital will also have fault codes if something goes wrong but really you already know how to assess it if it seems to fail again. Mostly now it is your preference on if you would like a programmable or not.
I will certainly be here when you need me. You can always request me by putting in the title of your question "This question is forCustomer and that will let the other experts know you are requesting me and to not respond. You are very welcome and thank you too! Good work!
Happy Sunday to you Dan!
Yeah, will give it some thought as also now wondering whether it's worth looking at a Nest or something. Will give it some thought, but thanks for all the help and also the how to get you again. Ta Dan
Hi Mike, sorry to have to come back to you, but the new thermostat arrived today (I decided to go for the exact same model to keep it simple), I've fitted it but it doesn't seem to have solved the problem. After fitting, I switched the electrics back on, it sounded like the boiler was igniting, but then it stopped and now it's unresponsive. I tried the bridge of points 3 & 4 and the boiler ignited. It went through the relevant sequence codes and then as soon as I took the bridge away it stopped.
I'm now at a loss... All the connections seem ok, wires in fine etc... As far as I can tell the external wires are all ok... ? no worries if you can't follow up, I may need to get someone here to look directly?