Honeywell 907 switching heating on and off every few minutes

[mandj]

Hoping someone can help me.
Just replaced old thermostat with Honeywell. When the room is at the required temperature the Honeywell is causing the boiler to fire for about a minute then switch off again, only to turn on again 5-10 minutes later. Is there any way to stop this, or would it indicate a problem with the system?

The boiler in a Worcester green star ri - approx 5 years old.

 

[Dan Robinson]

It is doing its thing. It is called TPi.

Worry more about your comfort levels rather than the internal goings on on the heating system.

 

[bolshy]

This is most likely TPI control, firing the boiler for short periods over it's programmed on time to try to match the boiler's output with the required heat load. It's an energy saving feature and cannot be disabled on this model. Someone jump in and correct me if I'm wrong please
Dan beat me to it

 

[Dan Robinson]

You can adjust various parts of it, but unless it is an oil boiler, there is little point unless you know how to make some pretty involved changes to the boiler parameters as well.

 

[snb]

you can alter the settings form minimum on time of 1 min up to a max of 5 mins.

you can also alter the number of cycles per hour from between 3 to 12.

normal settings for gas boilers are 1 min on with 6 cycles.

if you have 2 port valves on the system rather than 3 port then it is often best to change to 3 mins on with 6 cycles or 3 cycles.