Heaters no longer working

[bagofjuice]

I turned the thermostatic valves off on two heaters in unused bedrooms. They've been off for a long while, over a year.

I've turned the valves back on but the heaters don't get hot. I've tried bleeding them. Both pipes going into the rads are cold.

It's a Megaflow system. Here's a pick of the expansion tank and dial readings.

Is there anything I can do, or is it call the plumber time?

 

[gas112]

Give the valve part of the stat a sharp tap with a hammer there is a pin inside that sticks couple of hits should free it , Better if you can take the stat head off and give the pin a sharp tap

 

[bagofjuice]

Thanks, that sorted it - kinda. When I put the heads back on (set to max) the rads go cold again. The Thermostats are Myson TRV 2 Way. Looks like they both need replacing.

 

[gas112]

Be faulty heads if you can get the same just change the heads

 

[Whitespirit66]

The heads are available seperately.

http://www.heatingcontrolsonline.co.uk/myson-trv-way-replacement-head-p-331.html

 

[ianmcd]

Just interested - why did you think it was anything to do with the expansion vessel ?

 

[bagofjuice]

Thanks, I've ordered a few replacement heads.