The Efficient Home Forum

Hi,

I have an Evohome system running approx 11 zones - 6 x downstairs UFH + 5 x beds with TRV's - and hot water.

The system's been up and running without problems for three and half years until last week when the controller "forgot" all the names of the various zones and I had to re-enter them. Then, a few days later I woke up on Saturday morning to a cold home.

I had a look at the boiler - it had switched itself off. Then I looked at the Evohome controller - it wasn't talking to any of the CH zones or the hot water. I then checked the TRV's upstairs - they were all displaying COMMS FAULT. Then I had a look at Evohome control unit thing by the manifolds and it was a row of flashing red lights (normally they are all green). Finally, after a bit of Googling I checked the boiler relays for CH and HW and they were also in failure mode (solid red lights).

I spent a ton of time on Saturday morning making sure the pressure to the boiler was OK (it was), resetting the boiler, resetting the boiler relays and eventually turning the whole system on and off at the consumer unit. Finally I looked at the Evohome site and it suggested I "forgot" the relay units and re-connect them. I cautiously tried this for the HW but, predictably, I couldn't get it to reconnect.

Roll forward 24 hours and I'm now using the immersion heater for hot water as I've disabled the Evohome HW function (sigh). I've replaced every AA battery in every TRV & thermostat to no avail; at the moment none of the bedroom rads are working although I have had sporadic periods when they have worked. And the CH boiler relay has, on occasion, come back to life before going back into fail mode. There are currently lots of red (or maybe amber?) flashing lights on the manifold controller. There are comms faults on the TRV's. The HW & CH relays in fail mode. And the one "open circuit" rad upstairs is non-functional. Nothing is registering on the Evohome control unit or app.

Although, strangely, the 6 x UFH zones seem to have continued to function for reasons I can't fathom but which for which I am massively relieved. And this, of course, means that the boiler is functioning for this purpose at least.

Obviously I want get a suitably skilled heating engineer out to sort it and service it but am wondering if there are any simple steps I can follow to (a) get the CH systems comms back and (b) re-instate the hot water function.

Thanks

I've found a heating engineer who knows the system - I'll find out what's what later today.

01ForLondon wrote:I've found a heating engineer who knows the system - I'll find out what's what later today.

Did you check the batteries in the CS92A? If they have gone flat it will be causing the issues you have as it will 'RF signal jam' the whole system.

The EVOHOME Shop wrote:

01ForLondon wrote:I've found a heating engineer who knows the system - I'll find out what's what later today.

Did you check the batteries in the CS92A? If they have gone flat it will be causing the issues you have as it will 'RF signal jam' the whole system.

Thanks for getting back to me; they were possibly the cuplrits as they were very low and, to my knowledge, have never been changed since the system went in 3.5 years ago.

A secondary problem was probably caused by me; the engineer showed me the correct procedure for changing the TRV batteries - I wasn't re-binding them so that might explain why I ended up with the UFH working but not the rads.

Anyway, I'm a happy user again. My wife went through the Honeywell site 1st thing Monday to find an engineer and he was here by lunchtime. He re-programmed everything and explained a lot of stuff I hadn't known before. And, best of all, he's now going to provide an annual service of the boiler, water cylinder and Evohome system.

Summary; excellent technical backup from Honeywell.

01ForLondon wrote:Thanks for getting back to me; they were possibly the cuplrits as they were very low and, to my knowledge, have never been changed since the system went in 3.5 years ago.

Yep, they need to be changed annually to prevent this from happening. Good to hear you have it resolved though.

The EVOHOME Shop wrote:

01ForLondon wrote:Thanks for getting back to me; they were possibly the cuplrits as they were very low and, to my knowledge, have never been changed since the system went in 3.5 years ago.

Yep, they need to be changed annually to prevent this from happening. Good to hear you have it resolved though.

It's a good bit of kit. Now I've found the support I need going forward, I'm very happy. Great to see you guys take that part seriously. Not all vendors do but it's important.

01ForLondon wrote:
Thanks for getting back to me; they were possibly the cuplrits as they were very low and, to my knowledge, have never been changed since the system went in 3.5 years ago.

A secondary problem was probably caused by me; the engineer showed me the correct procedure for changing the TRV batteries - I wasn't re-binding them so that might explain why I ended up with the UFH working but not the rads.

Intrigued by that. My installation is only a year or so old, so I've only had to change two sets of batteries on TRVs, but I didn't seem to need to rebind them.

lloyd wrote:

01ForLondon wrote:
Thanks for getting back to me; they were possibly the cuplrits as they were very low and, to my knowledge, have never been changed since the system went in 3.5 years ago.

A secondary problem was probably caused by me; the engineer showed me the correct procedure for changing the TRV batteries - I wasn't re-binding them so that might explain why I ended up with the UFH working but not the rads.

Intrigued by that. My installation is only a year or so old, so I've only had to change two sets of batteries on TRVs, but I didn't seem to need to rebind them.

The original installer just told me to pop the lid off, flick the metal catch thing and replace the batteries.

This fella said;

- unlock the TRV and lift it off
- wind the black cog wheel thing back fully anti clockwise
- replace the batteries in the TRV
- press the button on the lower front part of the TRV until you see a message on the little screen (I think it said "Clear")
- then replace the TRV

News to me.

Hope this helps

https://www.youtube.com/watch?v=4L5ZWvRsoJ8

and here
https://www.youtube.com/watch?v=kEAD-IkXRrY&t=6s

01ForLondon wrote:The original installer just told me to pop the lid off, flick the metal catch thing and replace the batteries.

This guy knew what he was talking about, with exception of recalibrating the Radiator Controller afterwards...

01ForLondon wrote:This fella said;

- unlock the TRV and lift it off
- wind the black cog wheel thing back fully anti clockwise
- replace the batteries in the TRV
- press the button on the lower front part of the TRV until you see a message on the little screen (I think it said "Clear")
- then replace the TRV

News to me.

This guy has zero clue...