Plumbing Questions? Ask a Plumber for Answers ASAP
Hi . your programmer has failed. to verify this you can take the programmer face off , revealing the wiring and add a wire link between live and 3 . this should make the hot water on
Hi . this might not be 3 on thus model. Just checked the manual. Once you have the wiring exposed then you will have live and neutral and two others , let me know which ones are wired
Thanks. I did wonder about that. So simply connect Live with pin 3 with a new wire and turn the mains back on to test. If that works I am guessing that will prove the programmer is at fault. Out of interest for the CH do you know which pin that is on - I'll try and find a wiring diagram if not. Can I get back to you when I have tried that?
Ok thanks - I'll take a look. May be in a while but definitely today - hope that is OK.
Hi I have found the wiring diagram and pin 3 does correspond to HW on. This is not currently connected. I did notice there was a disconnected black core but I have not identified what this is. It looks like it was intentionally disconnected and is a spare. I think your suggestion of connecting live to pin 3 is a good test. I'll try this and let you know. At least this will prove the programmer is at fault. Thanks
Hi . I forgot that these act as they wiring centre for the whole system . what wires have you got on numbers 2 to 4?
You can get a programmer to replace the ep2 , any of the ep2000 models. My only concern is that you might end up retracing all the wiring .
So 2 is CH off and 4 is CH on
Ok .if 4 is CH on , then link 4 and live and the heating should run . does it show what one is hot water on?
HW on number 3
thanks I'll connect L and 4 only as a temporary thing to prove it is the programmer at fault
Try routing through the hot water on as well , because if you have a 3 port valve the heating relies on a route through the hot water, where as the hot water is more direct as the valve is designed to bfail safe to hotvwater. This dosntvmatter if you have two two poet motorised valves
Hi . just to let you know I will be unavailable for the next couple of hours , shopping duty calls unfortunately.
Hi, so I connected L and 4 and also tried L and 3 (I was mistaken before - pin 3 is actually for HW on). In both cases however the boiler fan did not come on. Additionally, the programmer lights no longer came on and the thermostat LED did not come on. After I removed the link the programmer came back on. Does this imply that that there is another fault somewhere? Thanks
I just had a thought, I still had pin 5 (CH off connected) - should that have been disconnected as part of the test?
No . it could be that the previous installers just wired the system up differently . which happens and is always difficult to sort . the boiler can be tested by using the link in the boiler from live to switched live. I'm sorry but just on way shopping ,back in a couple of hours , so sorry but I have to do . if you can be patient we can carry on then , Toby
Hi just letting you know I'm available
sorry for the delay. I tried bridging live and 3 but the boiler did not fire. I have a horrible feeling it might be a fault with the pcb (I don't think the boiler fuse is accessible easily and it is a compressed system so may not be wise for me to mess with that
I would like to rule out a fault with the boiler. Could you put a link between live and switched live and see if the boiler starts up ?
Is there an easy way to confirm which pin is switch live for the boiler? thanks
I think in the netaheat it says live neutral earth and switched live.
Ok the only trouble is that I only have access to the wiring behind the programmer which I think is the main wiring centre so it is going to be tricky to identify
Just looking at netaheat wiring. You might have to see what colour wire is connected in the boiler to switched live .
Sorry this isn't a quick one to answer , but I will stay with it till its sorted
Thanks. Daft question, but presumably I'd need to take apart part of the boiler to inspect the cable (hard to explain over chat) but the main boiler cable is buried behind plaster
Thanks - it is not a straightforward issue so appreciate your patience
The panel under the boiler is held by one screw underneath .then it just pulls out and the wiring is all there visible .its fairly easy to take off
Ah thanks. I'll take a look
Hi . I was just looking at the ep2 wiring guide again . it differs depending on your system . do you know if you have 2 two port motorised valves ( one for hot water and one for heating) or a 3 port valve to do both
hi it is a mid position valave
Hi . just reviewing all the info you have given and I'm certain it is the programmer. You have no power to the room stat which is routed through the programmer .The ep2000 series will fit onto that back plate . but I will continue testing with you as well .,
Ok thanks. Sorry for being anal - is there a way to prove it short of purchasing a new one. The only surprise was that bridging live and 3 did not cause the boiler to fire up. Thanks
every one apart from 2. 1-5 is the link and I only measured voltage across 5 and Neutral.
Hi tried replacing the boiler and a live link between 3 and 4 but the boiler still does not fire up and the room stat does not call for heat. Looking like the boiler but the 1A fuse has not gone. Thanks
yes I have accessed the boiler wiring and done the following tests.
1) I took off the room stat and bridged live to Normally Open (i.e thermostat switch cable that calls for heat) and measured voltage between the yellow Normally open core and neutral. I got 0 volts which is not correct as it was bridged to live. This implies either a break in the wire going to and from the boiler or something has gone open circuit on the boiler itself.
2) I identified the boiler brown core which was connected via a terminal block to what I believe is switch live (black core with brown tape). I then connected disconnected the black core and in its place connected the flex live. I ensured that neural was connected to the programmer. When switched on the boiler did not fire. Therefore the open circuit must be in the boiler
3) I checked the 1A boiler fuse - this was OK.
4) so it looks like something is open circuit on the boiler - some sort of switch not operating perhaps?