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Ardent Engineering
Ardent Engineering, Engineer
Category: UK Plumbing
Satisfied Customers: 91
Experience:  Registered Gas Installer
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heating not working on ecotec 837 plus water fine

Customer Question

heating not working on ecotec 837 plus water fine  C sign on display can't understand why not  thermostat on asking for more heat
Submitted: 4 years ago.
Category: UK Plumbing
Expert:  Ardent Engineering replied 4 years ago.

Ardent Engineering :

In-depth knowledge of Electrical and Mechanical engineering services. Vaillant boiler questions welcome.

Ardent Engineering :

Hi there,

Ardent Engineering :

could you be more specific about what is on the display?

Ardent Engineering :

Also, can you confirm how you have ensured the thermostat is calling for heat?

Customer:

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

Ardent Engineering :

I see, is it a wireless thermostat?

Customer:

yes wireless

Ardent Engineering :

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.

Ardent Engineering :

What is your brand and model of thermostat?

Customer:

siemens rdh10rf

Ardent Engineering :

Thanks, XXXXX XXXXX on whilst I find the O&M manual

Customer:

but even given thermostat might not be working, shouldn't the boiler still work if I turn to radiator symbol?

Ardent Engineering :

Not necessarily

Ardent Engineering :

If there is no radiator symbol on the display, there is no demand.

Ardent Engineering :

The thermostat controls the boiler.

Ardent Engineering :

We can get to the bottom of this now though.

Customer:

ok will wait your advice! i had builders in today and the electricity was off for an hour today, all was well this AM

Ardent Engineering :

I have the manual for your Siemens thermostat :)

Ardent Engineering :

Ah, that probably explains it!

Ardent Engineering :

The receiver and transmitter maintain communication only when mains power is continuously available at the receiver (the transmitter is battery operated)

Ardent Engineering :

You will need to "resynchronise" the transmitter and receiver.

Customer:

excellent! how please

Ardent Engineering :

Do you have a copy of the manual for your Siemens thermostat?

Customer:

I don't of course, am a girl

Ardent Engineering :

Copy here in case you haven't

Ardent Engineering :

Well, it's well known that girls don't come with instructions!

Ardent Engineering :

ahem, sorry.

Customer:

i have to get off wall somehow

Ardent Engineering :

Yes, let me just have a look myself, it isn't a common model.

Customer:

thanks!

Ardent Engineering :

It looks like it does actually "snap" into place - though I can't see exactly how from the limited detail.

Ardent Engineering :

Have you tried pressing the "set" button just to confirm the receiver will close the switch inside?

Customer:

sorry where is set button

Ardent Engineering :

That will at least get your heating on in the meantime.

Ardent Engineering :

It's the elliptical shaped button on the receiver

Customer:

so dumb which is the receiver the thing on the wall?

Ardent Engineering :

Yes - the one connected to the boiler

Ardent Engineering :

The transmitter is the oner with the display

Customer:

have pulled display off wall

Customer:

shall I push reset

Ardent Engineering :

Just check the instructions, there is a sequence that you have to follow

Ardent Engineering :

I think there is a more detailed manual than this, give me a min to find it.

Customer:

i think we can reset display, sorry, can you explain receiver on actual boiler

Ardent Engineering :

You should press the Test and Learn buttons on the rear of the receiver unit (it's not on the boiler)

Ardent Engineering :

Sorry Transmitter unit!

Ardent Engineering :

Then press Reset on the front of the receiver.

Ardent Engineering :

The receiver isn't "on" the boiler, but it will be wired to it and hence fairly close-by

Ardent Engineering :

So to summarise:

Ardent Engineering :

1. Rear of receiver unit - press Test and Learn

Customer:

can you tell me where the receiver might be - can't seem to see it? have reset receiver

Ardent Engineering :

Sorry, it's very confusing isn't it!

Ardent Engineering :

The receiver can be identified by one small, round lamp at top-centre, mid-right and two small buttons bottom right.

Customer:

have found the elliptical device near the boiler.... what do we do again?

Ardent Engineering :

The transmitter is the device with the large round rotary knob and LCD display that you alter the temperature with.

Ardent Engineering :

Press RESET on the receiver.

Ardent Engineering :

Press TEST and LEARN on the transmitter

Customer:

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

Customer:

neither led on receiver is working?

Customer:

are you there

Ardent Engineering :

Hi sorry, I've been trying to make a link between your last statement and the (poor) instructions

Customer:

ok thanks!

Ardent Engineering :

If you press SET on the receiver is there any response?

Ardent Engineering :

I see what you mean now - yes, RESET must be done by pressing those two buttons simultaneously.

Ardent Engineering :

The only problem is, it sounds like the buttons are not labelled as per the instructions I'm currently viewing.

Ardent Engineering :

If a button is labelled OVERRIDE however, that should close the switch to get your heating on whilst you fathom the reset.

Customer:

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.

Customer:

If there's no mains power to the receiver would that prevent the reset buttons from having any effect?

Ardent Engineering :

Yes, it would - the receiver requires mains power

Customer:

I think that might be the problem then. For some reason the receiver is not getting power which has snookered us

Ardent Engineering :

I would have expected it to be supplied from the same source as the boiler though - unless it is installed relatively remotely

Customer:

We've checked the fuse box and all fuses are ok.

Ardent Engineering :

OK, well there is a way round that

Ardent Engineering :

You can bypass the thermostat in the boiler's control panel

Ardent Engineering :

You will need some very basic competence with electrical though

Customer:

erm, ok. will give it a go

Ardent Engineering :

It's very simple.

Ardent Engineering :

You need to remove the case of the boiler.

Customer:

ok we are doing that, blimey

Ardent Engineering :

Flip the control panel down (if you can get this far, there is no reason why you can't get all the way).

Customer:

we are going to get all the way!

Ardent Engineering :

Now isolate the power to the boiler at the Fused Connection Unit

Ardent Engineering :

(that's the wall outlet, not the boiler's power switch)

Customer:

done

Ardent Engineering :

Good, now open up the upper part of the back of the control panel - it swings open to reveal the wiring terminals

Ardent Engineering :

If you're stuck check Page 26 here:

Customer:

ok done

Ardent Engineering :

Good, now identify terminals 3 and 4

Ardent Engineering :

They should have a wire connected to each.

Customer:

ok

Ardent Engineering :

Remember or make a note of which goes in which before you remove them

Customer:

ok

Ardent Engineering :

Then find a piece of wire that you can use to make a link between terminals 3 and 4 - 70mm long should be fine

Ardent Engineering :

I will have to leave the responsibility of carrying this work out safely to you, but it's not rocket science.

Customer:

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

Ardent Engineering :

Once you have successfully bridged 3 and 4, you have effectively bypassed the thermostat.

Ardent Engineering :

neither should have a green/yellow wire in there...

Ardent Engineering :

But they are directly next to each other - check the link Page 26 for clarification

Ardent Engineering :

It even shows the link in there on that diagram

Customer:

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

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