Thinking of adding the hot water kit to my Evohome

[G4RHL]

I think the focus on this start/stop aspect came from the EVOHOME menu options regarding minimum runtime and number of cycles per hour. The reality is, I don't think it makes a lot of difference with a zoned set-up, for the very reasons we are discussing here, particularly regarding the effects of small zones (such as a single room) combined with boilers with no, or limited modulation capability. The fact is the boiler will cycle more with EVOHOME than without it. I would still like to know what default settings EVOHOME uses with s-plan/y-plan set-ups where the options disappear, but I am starting to think this has had more emphasis than is warranted.

There is no doubt my boiler cycles more now with Evohome but on the other hand I am beginning to see drops in my gas consumption. I did not install Evohome for that reason. It's a nice bonus. What I do find though is that often my boiler cuts out but the pump is left in over run for good reason but the benefit is that heat is continued to be circulated to relevant zones, it is not being lost in my downstairs loo. This morning, monitoring what was happening, optimisation switched the boiler on at 05:44 for a zone not needing to be at 20C until 06:40. It was 16.5 at time of switch in. By 06:15 the temperatue was 19c. The boiler was switche'd off but the pump continued circulating residual heat for some time. I suspect the boiler left the pump in over run because the water was hot and only one zone was being heated as so far as aware Evohome does not control the firing of the boiler and the running of the pump independently when it sees the need - or does it?!

[erik]

Not sure if you have Opentherm or On/Off. But with On/Off, it certainly does not control the pump.

My boiler runs the pump for 5 minutes after every time the thermostat goes Off.