What does a boiler do when the CH water is up to Temp

[aelitaman]

So I have a WB 400, I have no thermostat on the system, trvs on rads and a timer.

I have read the manual and it says that when the water returning to the boiler is up to temp then the burner switches off, the pump will run for a short time to dissipate heat then turn off.

I can see how this is correct with a thermostat, because the thermostat will fire up the boiler when the temp falls.

But I do not have thermostat only a timer so how does the boiler know when it needs to restart the burner again to heat the CH water?

Is the manual wrong? When using only a timer does the pump still run after the burner has shut down and when the returning water is below a certain temp the boiler kick in?

TIA

 

[DaleRCL]

The boiler itself will have a thermostat on it and when the programmer tells the boiler to come on and off, the stat on the boiler will control how hot it gets. Not a very efficient method but at least you have TRVs.

 

[mysteryman]

You could usefully have a room thermostat fitted, preferably in the hall with no TRV on that radiator.

 

[ajrobb]

You could usefully have a room thermostat fitted, preferably in the hall with no TRV on that radiator.

This would be especially useful if you have poorly insulated pipes running under a suspended ground floor (or anywhere outside the heated 'envelope'). Your current system would keep these pipes hot with the pump running and losing heat all the time you have the heating on. With a room thermostat, the pump will turn off and these pipes can cool down and lose less heat.

 

[aelitaman]

Thanks for the answers.

So I have a Drayton LP programmer and it is located in the hall. So another quick question if a Thermostat is to be added is the thermostat wired into the LP programmer or wired into the boiler?

TIA

 

[Axel]

You don't need to remove any TRV - just leave it on MAX.