Boiler relay activated with all zone valves closed

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bucket123
Posts: 9
Joined: Sat Feb 15, 2020 5:23 pm

Re: Boiler relay activated with all zone valves closed

Post by bucket123 »

Yes, I have a WiFi model and I'll give Honeywell a call.

Thanks for your help.
bucket123
Posts: 9
Joined: Sat Feb 15, 2020 5:23 pm

Re: Boiler relay activated with all zone valves closed

Post by bucket123 »

Talked to tech support at Honeywell.

Initially to the main help desk who seemed to think firing the boiler with no zones open was normal behaviour and part of TPI. I asked what possible reason there could be for firing the boiler and was told it was to 'measure' the system. I told them that the only measuring device was the temperature sensor of the EvoHome controller and that can't measure any effect with the CH zone valve closed.

I was advised to change the cycle rate to 3 cylces per hour and the minimum on time to 4 minutes which are recommended for an oil boiler but that was all I got...

Until put through to 'installer support'. They said that firing the boiler without zones open is definitely NOT what is supposed to happen. We then discussed possible comms issues. There are none... the system works fine most of the time. It simply exhibits this strange behaviour when the heating demand is low (e.g. 12%, 20%, 27%). I get occasional comms errors in the log but only two or three each month. This problem happens every day!

'Installer support' asked me to monitor the situation since changing my settings and get back to them if it happens again. They seemed to think the actuators may not be bound correctly. However, if that were the case, the system wouldn't work at all - whereas it works fine most of the time.
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Richard
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Re: Boiler relay activated with all zone valves closed

Post by Richard »

bucket123 wrote:Talked to tech support at Honeywell.

Initially to the main help desk who seemed to think firing the boiler with no zones open was normal behaviour and part of TPI. I asked what possible reason there could be for firing the boiler and was told it was to 'measure' the system. I told them that the only measuring device was the temperature sensor of the EvoHome controller and that can't measure any effect with the CH zone valve closed.

I was advised to change the cycle rate to 3 cylces per hour and the minimum on time to 4 minutes which are recommended for an oil boiler but that was all I got...

Until put through to 'installer support'. They said that firing the boiler without zones open is definitely NOT what is supposed to happen. We then discussed possible comms issues. There are none... the system works fine most of the time. It simply exhibits this strange behaviour when the heating demand is low (e.g. 12%, 20%, 27%). I get occasional comms errors in the log but only two or three each month. This problem happens every day!

'Installer support' asked me to monitor the situation since changing my settings and get back to them if it happens again. They seemed to think the actuators may not be bound correctly. However, if that were the case, the system wouldn't work at all - whereas it works fine most of the time.
The thing with Resideo technical support, is to get back to them the second you experience another problem and they should be able to advise a resolution.
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Bart
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Joined: Thu Dec 28, 2017 12:18 pm

Re: Boiler relay activated with all zone valves closed

Post by Bart »

bucket123 wrote: ... There are none... the system works fine most of the time. It simply exhibits this strange behaviour when the heating demand is low (e.g. 12%, 20%, 27%).
A question for a specialist. What component in the system actually generates a heat demand?
For example, A zone with an HR92 valve that is used also as temperature input shows 30% heat demand on the main controller screen. That 30% is coming from the HR92, or does the controller establish this based on some other input parameters?
bucket123
Posts: 9
Joined: Sat Feb 15, 2020 5:23 pm

Re: Boiler relay activated with all zone valves closed

Post by bucket123 »

Hi Bart,

The only component in the system which can create a heat demand is the EvoHome controller itself which acts as the thermostat for the entire single CH zone. That's it... dead simple. That's why this is such a puzzle. When the hot water is off, then the Boiler Control and CH zone demand are always equal in the system summary. If the CH is at 27% then so is the boiler. And yet, the boiler relay still occasionally activates the boiler without the CH zone relay activating the CH zone valve. So the boiler heats nothing except the bypass valve!
gary333
Posts: 4
Joined: Wed Oct 23, 2019 9:12 am

Re: Boiler relay activated with all zone valves closed

Post by gary333 »

I have i think similar issues. I've tried everything including technical support and they just keep saying it must be a comms issue. However, all the checks show excellent signal.

1) Boiler relay BDR91 showing a demand (can be various levels) but all of the HR92's are showing 0%
2) One or two of the HR92's showing a heating demand along with BDR91 however the system has been turned off from the controllers menu (and the HR92's show this)
3) Boiler relay BDR91 showing 0% along with all the HR92's at 0% yet the boiler relay still fires the boiler for a minute even though the system should be in off (5oC)

Getting to the end of my tether with it and thinking of chopping it in for the Vaillant Ambisense. When calling technical they told me the messages between device could be getting corrupted. However, surely if the controller knows it should be off and the TRV's show the correct off setting where is the demand coming from. Seems to me that the relay must do more than simply turn on or off the boiler.
bucket123
Posts: 9
Joined: Sat Feb 15, 2020 5:23 pm

Re: Boiler relay activated with all zone valves closed

Post by bucket123 »

I'm perfectly certain it's a bug in the EvoHome software.

Their default fall-back position of 'oh it must be a comms error' just doesn't follow.

I think they need a decent software engineer to debug their code.
Eniodi
Posts: 25
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Re: Boiler relay activated with all zone valves closed

Post by Eniodi »

I'll second this. I'm about to get onto tech support. This is 100% a software fault, since I can force updates over comms and numbers reported across my system tally.


I have had multiple cases this week - the controller claims two rads calling for heat at 20% and 35%. The HR92s both report the same set point and room temperature as the controller shows, yet the valve is fully closed and the rad is cold. The boiler is firing and pump is going. If I increase the set point by 0.5 degrees either at the controller or on the HR92 dial the valve immediately opens and the I feel hot water coming through immediately.

This is a REAL problem. It seems that once *stuck* only a manual intervention kicks it back into working correctly. If I do nothing the room continues to get colder and even though the supposed heat demand % increases, the rad valve remains closed. The boiler is firing madly the whole time.

Fortunately I have two towel rads with no TRV, so at least I have a return flow back to the boiler, otherwise the system would be under imbalanced pressure. It does mean my bathroom is getting crazy hot while the bedroom calling for heat remains cold.


I had noticed a suspicious change recently. The outside temperature reported on the Evohome controller was permanently stuck on 8C for days or weeks, even though the real temp was above 18C. I figured this was a comms issue with the weather service, but didn't worry because I understand it didn't affect the heating logic. Yesterday I noticed that the controller no longer reports outside temperature at all - it's gone. Makes me wonder if there has been a recent firmware upgrade that has shafted my system up.
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