Central heating turns off early hours in morning

[VBaskaran]

hello experts,

I am not a DIY plumber, just a home owner who had a plumber come in to fix a couple of things at home.

changed 2 port valves for the boiler
removed some unwanted components in the water softener pipeline that was reducing the water pressure
increased water pressure on the incoming line from mains.
fixed a radiator that wasn't heating evenly, presumably by sucking heating loop and refilling it

But doing all of this, he may or may not have introduced a new problem which I wanted to get advice on from you experts

Every night since the plumbers visit, the central heating turns itself off from roughly 2am-4.30am. no matter what I do, it just would not turn on. restart boiler, check heating loop pressure and increase it if needed. Nothing seems to work and heating magically turns itself back on around 4.30am.


I have a tado at and I have deleted the schedule, reset the tado from the Internet bridge and reconfigured it. it is running on manual completely. Nothing seems to have made any difference.

Do you guys have ideas as to what's causing the heating to turn itself off? Hot water seems okay at this time.

 

[Deleted member 120897]

It doesn’t sound like something the plumber has done. So nothing happens at this time, increase thermostat temp and nothing?

 

[VBaskaran]

No, heating just won't come on at all. We use tado at home, we raise the temp on tado and it shows it has called for heating on it with the (2 or 3) heating lines but heating wont come on. We usually leave it like that and heating comes back on around 5ish again. Sounds strange.

 

[Deleted member 120897]

Could be one of the motorised valves. Do you know which brand was fitted?

 

[VBaskaran]

it's the Drayton Motorised valve 27100 2 port ZA5/679-2

 

[Deleted member 120897]

it's the Drayton Motorised valve 27100 2 port ZA5/679-2

If you’re comfortable and competent remove the head cover, I’ve had a few with loose motor screws on these, which could be sticking.

 

[Vinoth]

If you’re comfortable and competent remove the head cover, I’ve had a few with loose motor screws on these, which could be sticking.

Just been watching videos on youtube about this now, looks comfortable. But the plumber just called back, coming in today. hopefully he should be able to identify the problem.am hoping it is the motorised value. Thanks for your help.

 

[Chuck]

Just a guess, but I suspect that it will turn out to be the system thinking it needs to give priority to heating a hot water cylinder between 0200 and 0430.

These 'smart' control systems are so over-complicated and highly-strung they sometimes need a therapist rather than a plumber.