Boiler making noise after drain and refill

[Mrclean]

Hi
I had a plumber fit trv's which meant draining the system. I have a Vaillant turbomax plus combi,which since this work has started making kettling type noises, usually when the green light for the main burner comes on. It doesn't do it all the time and there are no fault codes. The plumber says it's just air, and I have bled radiators a few times, some seem to fizz when I do this with water trickling. I'm just worried it may be more serious but want to avoid calling gas engineer if it's not necessary. Any idea?

 

[Mottie]

How long ago was it done? Silly question probably but are you topping up the pressure each time you bleed it?

 

[CBW]

Are trv’s fitted to all radiators, or do you have one without?

 

[Mrclean]

It was done Friday. Yes I have been filling it.

 

[Mrclean]

Yes no trv in bathroom

 

[Harry Bloomfield]

I had a plumber fit trv's which meant draining the system.

Has one radiator been left without a TRV, where the room thermostat is located?

What control are you using with the Vaillant boiler?

 

[Harry Bloomfield]

Yes no trv in bathroom

Is there another one without a TRV, in the same room as you have your room thermostat? Usually that will be the hall radiator and the room thermostat installed in the hall.

 

[Mrclean]

There is trv where thermostat is but its on full as its a cold room. I have a tado thermostat

 

[Harry Bloomfield]

There is trv where thermostat is but its on full as its a cold room. I have a tado thermostat

What is 'on full' TRV or the thermostat?

Is the tado your room thermostat?

 

[Mrclean]

The trv is fully open. Yes tado is thermostat

 

[Harry Bloomfield]

The trv is fully open. Yes tado is thermostat

Which probably means your boiler will run near constantly, trying and failing to heat that very cold room - until switched off or it goes off on the clock.

The room stat is usually located in room which has a representative temperature, with no TRV on that rooms radiator. Sometimes the 'room' chosen is the hall, sometimes the living room. My thermostat is in the hall and my hall rad has no TRV.

The boiler noises suggest there is not enough water flowing through the boiler to remove the heat it is generating.

 

[BoilerBob]

Try refilling it from the bottom eg with a hose into a drain off cock that sometimes works well. Bob