Replacing Pegler TRV

[RodA]

The valve has gone faulty in my Pegler Terrier TRV, it doesn't turn the radiator off even on Frost. I've swapped the Termal head, still the same.

Can I replace the TRV without a system drain by freezing it?

I'm a bit concerned about the radiator outlet from the TRV, with it being a short length will it freeze with just a rag around it?

I'll turn off the header tank valve into the system before starting.

Any suggestions welcome.

Thanks

Rod

 

[D_Hailsham]

The valve has gone faulty in my Pegler Terrier TRV, it doesn't turn the radiator off even on Frost. I've swapped the Thermal head, still the same.

The pin is probably stuck.

Remove the head and check if you can press down the pin sticking up from the body. It should go down easily and then spring up.

If the pin won't budge some silicon lubricant may help.

 

[RodA]

I've already tried that, it moves up and down ok.

Thanks

Rod

 

[D_Hailsham]

I've already tried that, it moves up and down ok.

Does the rad go cold if you hold the pin down? If so, the valve body is OK; the problem must be in the head.

You can hold the pin down as follows:

Set the head to Max and remove it
Put a small coin, or similar, in the head
Replace head
Turn head slowly towards lowest setting until it won't turn any further.

 

[RodA]

I've exchanged the head from another radiator, still the same. I've also replaced the head with a plastic lock down cap, still the same.

Rod

 

[D_Hailsham]

I've exchanged the head from another radiator, still the same. I've also replaced the head with a plastic lock down cap, still the same.

Then you have proved that the valve body is faulty.

Fit decent valve next time, e.g a Drayton or Honeywell.

Now for you original question about draining down.

As you have an open vented system with header tank you can use the "bung" method. Get a Drayton Drain Easy kit from your local DIY shed or plumbers merchant and follow the instructions. You will then be able to change the TRV without draining down or freezing the pipes.

 

[gas112]

And what if he has a primatic cylinder???

 

[D_Hailsham]

And what if he has a primatic cylinder???

Then it's back to drain down or freezing.

 

[gas112]

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