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In-depth knowledge of Electrical and Mechanical engineering services. Vaillant boiler questions welcome.
could you be more specific about what is on the display?
Also, can you confirm how you have ensured the thermostat is calling for heat?
hi, just the letter C and the temperature but not much else on the thermostat it has an upward arrow and current temp says 14C but request is for 22C
I see, is it a wireless thermostat?
This could be fault with the thermostat, as if the boiler had a demand it would display a radiator symbol at the lower edge of the display.
What is your brand and model of thermostat?
Thanks, XXXXX XXXXX on whilst I find the O&M manual
but even given thermostat might not be working, shouldn't the boiler still work if I turn to radiator symbol?
If there is no radiator symbol on the display, there is no demand.
The thermostat controls the boiler.
We can get to the bottom of this now though.
ok will wait your advice! i had builders in today and the electricity was off for an hour today, all was well this AM
I have the manual for your Siemens thermostat :)
Ah, that probably explains it!
The receiver and transmitter maintain communication only when mains power is continuously available at the receiver (the transmitter is battery operated)
You will need to "resynchronise" the transmitter and receiver.
excellent! how please
Do you have a copy of the manual for your Siemens thermostat?
I don't of course, am a girl
Copy here in case you haven't
Well, it's well known that girls don't come with instructions!
i have to get off wall somehow
Yes, let me just have a look myself, it isn't a common model.
It looks like it does actually "snap" into place - though I can't see exactly how from the limited detail.
Have you tried pressing the "set" button just to confirm the receiver will close the switch inside?
sorry where is set button
That will at least get your heating on in the meantime.
It's the elliptical shaped button on the receiver
so dumb which is the receiver the thing on the wall?
Yes - the one connected to the boiler
The transmitter is the oner with the display
have pulled display off wall
shall I push reset
Just check the instructions, there is a sequence that you have to follow
I think there is a more detailed manual than this, give me a min to find it.
i think we can reset display, sorry, can you explain receiver on actual boiler
You should press the Test and Learn buttons on the rear of the receiver unit (it's not on the boiler)
Sorry Transmitter unit!
Then press Reset on the front of the receiver.
The receiver isn't "on" the boiler, but it will be wired to it and hence fairly close-by
So to summarise:
1. Rear of receiver unit - press Test and Learn
can you tell me where the receiver might be - can't seem to see it? have reset receiver
Sorry, it's very confusing isn't it!
The receiver can be identified by one small, round lamp at top-centre, mid-right and two small buttons bottom right.
have found the elliptical device near the boiler.... what do we do again?
The transmitter is the device with the large round rotary knob and LCD display that you alter the temperature with.
Press RESET on the receiver.
Press TEST and LEARN on the transmitter
reset i think on the receiver it is override and learn at the same time too? they both have reset linked to them the two buttons are override and learn F
neither led on receiver is working?
are you there
Hi sorry, I've been trying to make a link between your last statement and the (poor) instructions
If you press SET on the receiver is there any response?
I see what you mean now - yes, RESET must be done by pressing those two buttons simultaneously.
The only problem is, it sounds like the buttons are not labelled as per the instructions I'm currently viewing.
If a button is labelled OVERRIDE however, that should close the switch to get your heating on whilst you fathom the reset.
we've pressed them simultaneously, but appears to have no effect. There are two tiny LEDs on the surface of the receiver, but neither are illuminated.
If there's no mains power to the receiver would that prevent the reset buttons from having any effect?
Yes, it would - the receiver requires mains power
I think that might be the problem then. For some reason the receiver is not getting power which has snookered us
I would have expected it to be supplied from the same source as the boiler though - unless it is installed relatively remotely
We've checked the fuse box and all fuses are ok.
OK, well there is a way round that
You can bypass the thermostat in the boiler's control panel
You will need some very basic competence with electrical though
erm, ok. will give it a go
It's very simple.
You need to remove the case of the boiler.
ok we are doing that, blimey
Flip the control panel down (if you can get this far, there is no reason why you can't get all the way).
we are going to get all the way!
Now isolate the power to the boiler at the Fused Connection Unit
(that's the wall outlet, not the boiler's power switch)
Good, now open up the upper part of the back of the control panel - it swings open to reveal the wiring terminals
If you're stuck check Page 26 here:
Good, now identify terminals 3 and 4
They should have a wire connected to each.
Remember or make a note of which goes in which before you remove them
Then find a piece of wire that you can use to make a link between terminals 3 and 4 - 70mm long should be fine
I will have to leave the responsibility of carrying this work out safely to you, but it's not rocket science.
just to check 3 and 4 are terminals right next to each other - one has a brown wire attached, the other has a green and yellow
Once you have successfully bridged 3 and 4, you have effectively bypassed the thermostat.
neither should have a green/yellow wire in there...
But they are directly next to each other - check the link Page 26 for clarification
It even shows the link in there on that diagram
we think we have gone far enough!! thanks we will accept anyway but this doesn't feel right if you are complete novices like us F