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Plumberpro
Plumberpro, Plumber
Category: Plumbing
Satisfied Customers: 634
Experience:  Heating and plumbing answers. 20 years experience
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My central heating won't turn off. The boiler display is showing

Customer Question

My central heating won't turn off. The boiler display is showing a calling for heat even though the programmer is turned off. The actuator, room thermostat & motherboard have all been replaced but it still won't do as the pogrammer says!
Submitted: 1 year ago.
Category: Plumbing
Expert:  Andrew Smith replied 1 year ago.
When it is on when it should be off, is the lever on the motorised valve slack or tight?
Customer: replied 1 year ago.
Tight.
Expert:  Andrew Smith replied 1 year ago.
Ok, shut then - so only your hot water should be heating?
Customer: replied 1 year ago.
If you mean the black lever on the bottom of the actuator it's in & difficult to move. The central heating is on not the hot water. The boilers display code is showing a communication fault & the programmer is showing all heating off. What do you think? I've had 2 plumbers here & neither of them could sort it.
Expert:  Andrew Smith replied 1 year ago.
We will get there.Do you have only one motorised valve?Does it have 2 or 3 pipes?
Customer: replied 1 year ago.
I have one motorised valve, 3 pipes.
Expert:  Andrew Smith replied 1 year ago.
Ok, only a couple of things that will keep the boiler running;1. A faulty 3 port or 2 port valve2. A faulty frost stat3. A faulty clock showing off when really on Do you have the make and model of the boiler?
Customer: replied 1 year ago.
Boiler is an Ideal Icos.
Expert:  Andrew Smith replied 1 year ago.
HE model?
Customer: replied 1 year ago.
It's an HE18.
Expert:  Andrew Smith replied 1 year ago.
Ok, when the boiler should be off but it is hot, how many of the pipes in and out of the 3 port valve?Is it open to the heating but just the valve is stiff?It could be a faulty microswitch in the valve head or the valve is stuck open.
Customer: replied 1 year ago.
I'll check the pipes & get back to you. How do I know if it's "open to the heating but just the valve is stiff"?
Expert:  Andrew Smith replied 1 year ago.
The heating will get really hot.Take the head off and see if the spindle can move?
Customer: replied 1 year ago.
All 3 pipes to the actuator are hot. The spindle does move. But not very much, maybe 30 degrees.
Expert:  Andrew Smith replied 1 year ago.
With the head off, can you turn the heating on and off and see if the head moves where it attaches to the pin?
Customer: replied 1 year ago.
The head moves when I turn the heat water on at the programmer but not when I turn the central heating on.
Customer: replied 1 year ago.
I've received notification of your reply but your reply isn't displayed.
Customer: replied 1 year ago.
Our conversation seems have become one way. I haven't received any further responses from you. My heating is still on full blast & I'm no closer to resolving this problem. Please respond!
Customer: replied 1 year ago.
I'm not satisfied with this service. ***** ***** stopped communicating with me for no reason & I've been referred to another expert who hasn't made contact with me after 3 days of being referred. Very disappointed!
Expert:  Plumberpro replied 1 year ago.
Hi , sorry to hear about your help so far , Do you still require help? If you do I will try to help figure out your fault
Customer: replied 1 year ago.
Yes, still need help! To save time have you viewed the previous conversation with ***** *****?
Expert:  Plumberpro replied 1 year ago.
Yes I read the previous. The thing we need to establish is whether it is a boiler internal fault,ie pcb or an external control fault, ie clock ,room stat.The way to check this is to remove the switched live wire that comes from the controls and see if the boiler stops running.You will need to access the boiler wiring centre.follow the power leads in . Switched live should be L2
Customer: replied 1 year ago.
I've removed the PCB. Can you advise me in relation to the wiring diagram on pg 36 of the Ideal Icos manual (online) as the mains connector is sealed & cannot be accessed.
Customer: replied 1 year ago.
Sorry I meant page 37 which is a wiring diagram of the pcb. If we both work from the same page it'll be easier to understand from my point of view.
Expert:  Plumberpro replied 1 year ago.
Hi , you have removed the pcb or the cover?The pcb needs to be in place.
Customer: replied 1 year ago.
I've removed the pcb to get to the connectors.What would you like me to do?
Expert:  Plumberpro replied 1 year ago.
Hi , I said access the boiler wiring centre. If you have removed the pcb then you will need to replace it. You need only access the incoming cables.(the live neutral earth and there will be a cable for controls. 31 internal controls page 24
Customer: replied 1 year ago.
I've isolated the SL at L2. Boiler is not coming on. Display is showing 0 so it's getting power.
Expert:  Plumberpro replied 1 year ago.
Hi , ok so it must be a controls issue. What clock and room stat do you have
Customer: replied 1 year ago.
Room stat is a Drayton & it's new. If by clock you mean programmer it's a Drayton Lifestyle LP522, also new.
Customer: replied 1 year ago.
I've looked at the programmer wiring & there's no cable at the CH off terminal. There is a spare unconnected cable. When I connect this to the terminal it creates a short & trips the MCB. I've disconnected the room stat & the SL at the boiler is still at 240v.
Customer: replied 1 year ago.
More info: The incoming permanent live & switch live at the boiler were the wrong way around. I've swapped them but now I seem to have the opposite problem. The hot water side works fine but the CH side is unresponsive. Look forward to hearing from you.
Expert:  Plumberpro replied 1 year ago.
Hi , sorry for the late reply. I received an email you had replied but it wasn't showing in the question list.The ch off and hw off arnt needed for your combi boiler system..The boiler needs a permanent live as well as switched live to fire the central heating..In the wiring for the lp522 it only needs 3 wires ,permanent live and neutral and a wire in 4 (central heating on). The ch on is the switched live run ing back to the boiler. I
Expert:  Plumberpro replied 1 year ago.
If you have a room stat then the ch on wire will run to common on room stat and out to boiler switched live
Customer: replied 1 year ago.
The programmer has 5 wires. Live, neutral, HW on, HW off & CH on.
Expert:  Plumberpro replied 1 year ago.
Your icos is a combi or conventional boiler, ie seperate hot water cylinder?
Customer: replied 1 year ago.
Yes, there's a separate hot water cylinder.
Expert:  Plumberpro replied 1 year ago.
Hi , sorry for the delay. Could you take out and isolate the ch on from the programmer please and see if the central heating g goes off , thanks
Customer: replied 1 year ago.
Since swapping the PL & the SL at the boiler the CH is permanently off. The problem is now it won't come on!
Expert:  Plumberpro replied 1 year ago.
Hi , ok , best to swap them back then , but could you just put the pl in and see if the heating is off. This will prove it is a controls issue, thanks
Customer: replied 1 year ago.
OK. Now the central heating is off. So it's a controls issue. How do we proceed?
Expert:  Plumberpro replied 1 year ago.
Ok , can you isolate hot water off in the programmer, thanks and see if the heating stops running