crumbling TRV heads - whats the odds

[mariaduffy]

Hi again guys - thanks again for helping me sort my central heating recently (you know who you are )

I swear my central heating is jinxed. I have Myson 2 way TRVs fitted to all but one rad (the one in the same room as the stat). This week not one but two TRV heads I noticed were sitting wonky. I unscrewed the ring/knurl and the 'legs' just fell to bits in my hand. After much investigation my son admitted to killing one TRV with his ball but I swear the other in the bathroom has literally just crumbled !! There are no white stress marks that you get with plastic breakage on the bathroom one - there are on the 'death by football' one. Johnny couldn't kick his ball in our tiny bathroom, I can hardly swing a lipstick in it

Coincidentally, the bathroom rad gets hottest (untouchably so) in the whole house. Is there any chance that the legs could have been brittled by extreme heat? Has anyone seen such a phenomenon in their travels?

Just one more thing guys - Can I replace these Mysons with Danfoss TRV heads without having to replace the whole valve. In other words are all the valves standardised?

 

[swbjackson]

The valves aren't standardised. Even if the threads are the same there is no guarantee that the travel within the valve is the same.

Mike

 

[mariaduffy]

Thanks Mike - I am going to try to get exact replacemnts online, would you recommend any merchants online that are reliable/tructworthy that might stock Myson 2-way heads - unfortunately Screwfix don't

 

[swbjackson]

Don't use online merchants much I'm afraid. Try a google search.

Mike

 

[gas4you]

You'll probably find it's just as cheap to buy the whole valve and just use the head.

Not many will stock just the heads.

 

[Softus]

Is there any chance that the legs could have been brittled by extreme heat?

Yes.

Has anyone seen such a phenomenon in their travels?

Yes.

Can I replace these Mysons with Danfoss TRV heads without having to replace the whole valve.

No.

In other words are all the valves standardised?

No.

 

[scatmanjohn]

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

 

[mariaduffy]

Thanks all who replied esp Scatman for the link. That is in fact the online merchant I was thinking of buying the head from but I have become weary/wary of poor online service. One glimmer of hope with the merchant in question is that it is registered with ISIS (strangely not with IDIS though )

For now I have been able to insert a tough plastic sweetie mould from a well known sweet packet which has an inverted dome shape. It remarkably fits exactly inside the knurl ring and when screwed down the valve pin/spindle closes. Now what are the odds of that....?