Hot water warming without instruction.

[Gjackson1972]

Hi there. I wonder if you can help me. I have a very recently installed Evohome system comprising of a display/controller, 8 Honeywell smart TRVs and a hot water controller.

The hot water seemed to have a mind of its own, so I adjusted the settings to check what’s going on. I set the following settings:

Stored hot water: hot water temp 65C, hot water overrun 0min, hot water differential 5C. The schedule for hot water is permantly OFF.

Despite this my hot water temperature fell to 47C by lunchtime today, then by dinner time it was back up to 57C.

I had set up a video camera on the receiver unit next to the boiler and can confirm the green “call” indicator light never illuminated during that time. I believe the central heating did come on during this time.

Any ideas why the hot water temp would rise without being called?

Many thanks in advance

Gary

[Richard]

If there is no demand on the hot water relay, then there is no demand on the valve. Temperature jumps with the CS92A are normally experienced when the CS92A is not very well located.

Any chance of some images of the installation of the relay boxes and CS92A?

[Gjackson1972]

Absolutely! No problem, please find photos of the set up as soon as I work out how to attach them.

[Richard]

OK, so firstly the CS92A and the BDR91 are much to close to each other and secondly they are virtually sitting behind that big metal object that is the cylinder... Bear in mind that RF transmissions cannot pass through the metal cylinder and you will then soon understand why evohome is having a hard time trying to turn the relay on and off and receive the correct temperature information from the CS92A wireless tank thermostat. These are RF devices and must be installed so they will work correctly.

Please see the information on this page - http://theevohomeshopforum.co.uk/viewto ... ?f=15&t=30

[Gjackson1972]

Many thanks, I will review that document and make adjustments. This was installed by a gas engineer while installing a new boiler, it was not DIY. Hopefully simply repositioning will help.

Do you think repositioning this one unit as shown in the attachment will be sufficient? I think I just about have 30cm elsewhere.

[Richard]

Many thanks, I will review that document and make adjustments. This was installed by a gas engineer while installing a new boiler, it was not DIY. Hopefully simply repositioning will help.

Do you think repositioning this one unit as shown in the attachment will be sufficient? I think I just about have 30cm elsewhere.

Unfortunately some installers think they know how to do these things without reading the manual and then come the mistakes, as they don't know how evohome should be installed or how it operates.

If you have a clear wall where that single BDR91 is on its own, I would wire all the RF devices up that wall so you have RF line of sight with the evohome Controller and make sure the BDR91's and CS92A are well away from each other. This will mean extending the CS92A cable from its current position but this is perfectly acceptable.