Bulldog TRV heads

[Flintmcc1956]

Hi there,

I have a problem with the above heads, after a year or so the plastic body under the chrome ring which fixes them to the valve fractures and the heads fall off. I have checked the valves and they are functioning correctly.
Is it possible to buy replacement heads and more importantly for longevity ones with metal bodies and not the plastic. I have six radiators and system was installed by Calor Gas.
markings on the body are Bulldog >gene EN215 with a number 42 above.

I have looked on Amazon, and can source heads, just wish to make sure correct ones.

Thanks in anticpation.

John

 

[St0rmer66]

Yes the heads are straight replacement. Usually it takes many years for them to get that brittle though. Are you perhaps running the system very hot? (e.g. 80 degrees) as I can't think of anything else that would cause this to happen so fast.

 

[gas112]

been fitting bull dogs for coming on 20 years and never had them cracking unless kids etc hitting them

 

[Flintmcc1956]

System is run consistently at 21.5 to 22 degrees C...

Have to say that I have found similar behaviour on other makes of heads, it is just the Bulldog ones that were fitted to my current Central Heating system.

Does anyone on here know of a metal bodied connector, without the plastic internal parts which are in contact with the metal valve.

As the plastic in contact with the valve after quite a short time goes brittle and falls apart when you adjust the thermostat control.

I have attempted to rebuild some of these with araldite, but this only works for a short period of time. Due to the expansion stress placed on the head when the control is turned.

 

[St0rmer66]

You misunderstood what I said... Not the air temperature the room thermostat is set to. The boiler flow temperature is what I was asking.