Combi Heating - Hot rads downstairs, cold rads upstairs

RedBalloon

Woohoo - you people are amazing!

This morning I turned off all the rads downstairs and isolated one of the 2 bedroom rads that weren't working with it turned on max.

Then while i waited for it to hopefully heat up, I blew a hot hairdryer over the thermostatic valve connections (without unscrewing it) and turned the dial up / down. After a minute or so I could feel the hot water entering the radiator at the other end!

Went to the second bedroom and repeated and that started heating up too! 
Now all radiators upstairs and downstairs are on  

Edited to add - these great tips will no doubt help someone else in future too 

Eldi_Dos

Good result.

If you can manage to take the heads off the TRV, as per method described by TIW, once you have the pin rub a pencil up and down the shaft,the grapite will help lessen the chance of pin sticking in the off position. Only takes a couple of minutes per valve.

ThisIsWeird

RedBalloon said:

Woohoo - you people are amazing!

This morning I turned off all the rads downstairs and isolated one of the 2 bedroom rads that weren't working with it turned on max.

Then while i waited for it to hopefully heat up, I blew a hot hairdryer over the thermostatic valve connections (without unscrewing it) and turned the dial up / down. After a minute or so I could feel the hot water entering the radiator at the other end!

Went to the second bedroom and repeated and that started heating up too! 
Now all radiators upstairs and downstairs are on  

Edited to add - these great tips will no doubt help someone else in future too 

Great result!

Have to say, the hairdryer one was new to me.

As Eldi suggests, it's worth now taking action to hopefully prevent this from occurring again. Graphite may well be a good solution, but I prefer to use silicone grease as it should hopefully coat the pin better, and keep working over time.

If you remove the TRV head - easy to do - then check the pin. Make sure it's clean - if it isn't, then clean it! Use a tooth brush or whatever will do the job.

Then smear it with sili grease, pressing a nice bead down around the pin's base too. Press the pin downwards a few times, and release - the sili should be drawn in with each push. Make sure there remains a circle of sili around the pin base, and replace the head - the sili will keep on acting every time the TRV head operates.

(NB - this is silicone GREASE, not sealant!)

Albermarle

Eldi_Dos said:

If any of the pins are stuck in the closed position I have heard that heating valve body with a hairdryer can help free the pin.

I usually just manually pull the pin up with a pair of pliers, spray some WD40 on it ( silicone grease is probably better) and push it back down again. After doing this a couple of times the pin moves more freely.

Saying that though, the pipes to the thermostatic valves are cold.
If the TRV is stuck closed, then there is no flow so the inlet and outlet pipes will be cold.

Eldi_Dos

Am a bit wary of silicone grease, it is very difficult to remove if you get it in the wrong place.

Had a colleaque who washed overalls with it on them, ended up over drum of machine which he could not remove, resulting in having to replace quite a new machine which did not go down well.
I once inadvertently cleaned my van mirrors with a rag that had some on it, took weeks to get it completely off.

ThisIsWeird

Eldi_Dos said:

Am a bit wary of silicone grease, it is very difficult to remove if you get it in the wrong place.

Had a colleaque who washed overalls with it on them, ended up over drum of machine which he could not remove, resulting in having to replace quite a new machine which did not go down well.
I once inadvertently cleaned my van mirrors with a rag that had some on it, took weeks to get it completely off.

That's its beauty - it's pretty inert! So, yes, don't get it on anything you don't really want... (But, just how much did your colleague have on his overalls?!)

If you are dealing with rubber seals and washers, especially the type that have moving parts - tap spindles, tap spouts, valve seals, push-fits, exterior junction boxes with rubber seals, anything like that, it's the 'proper' stuff to use. You just need a smear on yer fingertip.

I would caution against using it on exposed items, tho', as it'll - like any grease - catch and accumulate dust over time, but I think under a TRV head should be safe. And it'll keep on lube'ing the spindle or pin in use, every time it moves.

Lost count of the things I've used it on. Fog-horn cistern washer? Give it a smear - it'll deaden the vibes.