New boiler, last rad heats up then goes cold

FataVerde

FreeBear said:

There are (I think) two different size threads used for TRV heads. 28mm and 30mm. The pins are sometimes different lengths too. The Drayton valve has a 30mm thread, and the pin protrudes 9.32mm from the body.

Yes, I eventually found some images of my Kudox TRVs, but they probably just paired them with their rads at the time and no longer produce them. I can't get the specs or the product. Mine were angled, but it;s the same product otherwise.

FataVerde

Mutton_Geoff said:

A quick note for wannabee rad balancers, my experience has been that most of the rads have the lockshield only half to one turn from fully closed to set them correctly whilst only one or two (at the far end of pipe runs usually) are half way or fully open.

Yes, the gas engineer didn't do any of that. I might give it a try but it's way above my pay grade. I had to take a crash course in boilers and heating systems just to get the right boiler and I'm quite happy with it.

ThisIsWeird

FataVerde said:

FreeBear said:

There are (I think) two different size threads used for TRV heads. 28mm and 30mm. The pins are sometimes different lengths too. The Drayton valve has a 30mm thread, and the pin protrudes 9.32mm from the body.

Yes, I eventually found some images of my Kudox TRVs, but they probably just paired them with their rads at the time and no longer produce them. I can't get the specs or the product. Mine were angled, but it;s the same product otherwise.

Could you post a nice clear pic of your headless Kudox valve body, please? One from the side, and one showing the top? I can compare that with the ones I have (I think Drayton).

When were these Kudox TRVs fitted?

FreeBear

FataVerde said:

Mutton_Geoff said:

A quick note for wannabee rad balancers, my experience has been that most of the rads have the lockshield only half to one turn from fully closed to set them correctly whilst only one or two (at the far end of pipe runs usually) are half way or fully open.

Yes, the gas engineer didn't do any of that. I might give it a try but it's way above my pay grade. I had to take a crash course in boilers and heating systems just to get the right boiler and I'm quite happy with it.

If you can bleed a radiator, you have all the skills you need to balance them. If a grumpy old bear like me can manage it, I'm sure you can too.

The head looks very much like an ECA brand I have here - A Drayton head will screw straight on.

FataVerde

ThisIsWeird said

Could you post a nice clear pic of your headless Kudox valve body, please? One from the side, and one showing the top? I can compare that with the ones I have (I think Drayton).

When were these Kudox TRVs fitted?

They were fitted last April! Ridiculous. The others in the house have 'bulldog' as brand and they look like they've been there for 10years at least lol

FataVerde

FreeBear said:

If you can bleed a radiator, you have all the skills you need to balance them. If a grumpy old bear like me can manage it, I'm sure you can too.

The head looks very much like an ECA brand I have here - A Drayton head will screw straight on.

Yes, it looks very similar to drayton. The pin however looks a bit taller. Mine is about 8mm. https://www.screwfix.com/p/drayton-white-angled-thermostatic-auto-balancing-radiator-valve-body-15mm-x-1-2-/175RG

FreeBear

FataVerde said:

FreeBear said:

If you can bleed a radiator, you have all the skills you need to balance them. If a grumpy old bear like me can manage it, I'm sure you can too.

The head looks very much like an ECA brand I have here - A Drayton head will screw straight on.

Yes, it looks very similar to drayton. The pin however looks a bit taller. Mine is about 8mm. https://www.screwfix.com/p/drayton-white-angled-thermostatic-auto-balancing-radiator-valve-body-15mm-x-1-2-/175RG

The diameter of the thread on the valve body is looking to be 28mm - If that is the case, Drayton heads won't fit unless you use an adaptor. Could well be easier to change the valve body as well as the TRV head.

FataVerde

FreeBear said:

The diameter of the thread on the valve body is looking to be 28mm - If that is the case, Drayton heads won't fit unless you use an adaptor. Could well be easier to change the valve body as well as the TRV head.

How do I measure that diameter? Is it the metalic ring on the TRV head that screw onto the valve? and do I measure the inside diameter without the 1-2mm of the ring itself?

FreeBear

Measure the body, not the ring.

ThisIsWeird

I'll try and post some photos and dims later.
FV, if you hold your removed head upside-down and turn the control, can you see the 'piston' inside move up and down too? It should, by a good 6mm or more.
And, on a rad with a head still fitted, could you also turn the control from min to max and back again a few times, and report what you 'feel'? It should feel more loose and easy to turn from 5 down to around 2-3, and become quickly obvious it's firming up, and slightly increasingly so as turned down further. Does it?