Boiler seems to be ignoring controller

[magunn]

I have a Honeywell eco home system but even with the heating switched off and the hot water at the temp set by the thermostats. Both wireless relays are off The boiler is still firing up. Why?

[ProDave]

What boiler, where, what fuel, and most important question, has it EVER worked properly with this controller, or did it work properly with a previous controller?

[Carrerahill]

48 minutes ago, magunn said:

I have a Honeywell eco home system but even with the heating switched off and the hot water at the temp set by the thermostats. Both wireless relays are off The boiler is still firing up. Why?

Firing up and doing what? Heating a cylinder or radiators, both?

 

Some boilers do exercises, some have a frost stat to protect from freezing, if this fails they can think it is colder than it is etc.

[magunn]

Sorry my initial post was rather vague

its a Honeywell evo home system.

Wall thermostat / control unit shows both the dhw and ch as off (see pic 2)

the relays that it controls also show both to be off( pic 1 )

yet something is overriding the controller and calling the boiler to fire up 24/7 and heat the radiators, even though the temp of the house is way above the 16c demanded.

Is there anything that can override the timer / thermostat

 

yes it has worked before and this started when we tried to solve a lack of hot water issue

Not sure what info you need about the tank other than it’s a thermal store system.

[ProDave]

So you DID change / fix something, the lack of hot water.  Just what did you change / fix / modify there?  THAT will be where your problem is.

 

Typically the heating controls would instruct a motorised valve (2 separate ones or a 3 position valve) to open as appropriate and a feedback switch on the motorised valve would fire the boiler when opened.  If you have messed with the motorised valves either physically or electrically they could now be stuck calling for heat.