Ideal logic 24 + heats radiators once then stops shows no fault !

[Leezo]

Hi all
Looking for some help please!
It concerns an ideal logic plus 24 combi.
When you switch the central heating on it fires up fine. All the radiators get up to temperature. It then stops and the radiators cool down. All good! They do not come back on, even when the room is noticeably cooler/ cold. If left for a number of hours you can eventually switch the CH back on and it will go through this cycle again.
Weirdly if you set the TRVs to say 3 they will heat to 3 and stop. If you then turn it to 4 it will start up, heat to 4 and stop again and nor re start.
The ideal logic engineer has been out twice. He says there is no fault on the boiler (as no fault code shows) which has acted like this since new. Is about 2 years old now. Engineer also dais its probably the room stat. And because it's not ideal he won't check it. Anyway the stat has been replaced and the problem is the same. All the TRVs have been changed and still the same. System had been checked for airlocks/ slipped inserts etc.
Can anybody suggest what the problem might be, many thanks : )

 

[AWheating]

Sounds like the boiler works fine, what stat/ controls do you have? Make and model

Is the room stat in the cold room? Away from a heat sorce?

 

[SavageW]

Does the heating come back on if you then turned your room thermostat up?

 

[Alpha man]

Room stat or wiring at it!

 

[Harvest Fields]

Have you got a timer built into the front of the boiler? Is the timer set on timed or constant/on?

 

[Leezo]

Have you got a timer built into the front of the boiler? Is the timer set on timed or constant/on?

Hi thanks for response, no timer on boiler.

 

[Leezo]

Sounds like the boiler works fine, what stat/ controls do you have? Make and model

Is the room stat in the cold room? Away from a heat sorce?

Hi
Thanks for response, the stat is in the best coolest place furthest away from any heat source. I will get back to you with the stat make and model. It's been changed once already to a different type of stat and still the same problem...

 

[Leezo]

Room stat or wiring at it!

Hi
Thanks for response, i'm starting to think it's a wiring issue but it's only two wires!

 

[Leezo]

Does the heating come back on if you then turned your room thermostat up?

Its at another house i will check as its been a while..

 

[Alpha man]

2 wires at the roomstat could be the issue depending on what roomstat you have!