simple question from newbie... rads not working

[willb5000]

hey all - am new to plumbing but willing to get wet!

My bedsit flat has a standard combi boiler heating water for the shower, kitch sink and bathroom sink and 4 rads (one in kitch, two in main room, and a towel rail). The hot water is fine and pressure good - but only one rad works in the main room, and the towel rail in the bathroom works. Rad in kitch and the next nearest (in main room) dont get hot though - they're both double panel double convectors I think. The kitch one used to get hot, the other never has... both are bled for air, valves appear to be 'on'.

Is this down to some sort of gunk build up maybe? Does it sound easy (ish) to fix please?

Any advice welcome! :biggrin:

Cheers

WillyB

 

[Anton]

Have the radiators that aren't working got thermostatic valves fitted to them ?
Are they turned up to maximum ?
With the high temperatures in this weather (depending where you are) the thermostats may not open.
If they are thermostatic valves on the radiators the valves could be stuck down on their seatings due to muck sludge. If you are in a bedsit above another bedsit, I wouldn't recommend trying a DIY fix unless the other tenant doesn't mind getting wet too.

 

[willb5000]

Thanks Anton - they are thermostatic... but haven't worked for a while (including when it was colder), but the others seem to come on ok though. I'm in the basement flat with (fake) wooden flooring so no big deal if there's a leak!

Would it make sense to buy a freeze kit (if so, any recs?) and try to take out the thermo valves to see what's going on? Is that pretty simple to do?

cheers
W.

 

[Riley]

Agreed I would be thinking it will be a fault with the TRVs. If you're confident to drain the system down then maybe give it a go. Failing that a plumber should be able to sort for you relatively quickly. Maybe post your location on the looking for a plumber section on here and there might be one of our lads in your location.

 

[willb5000]

Thanks guys

I'm in the basement so no danger of flooding anyone below - but I think the full drain may be beyond me - I know how to top up the boiler when the pressure gets low, but that's about it. Might it be worth getting a freeze kit and trying to remove the thermo valves to give them a good clean up? I was hoping to avoid calling a plumber just to save some cash!

Cheers

 

[Riley]

If you're not 100% hire an electric freezer. Aerosol ones can be a bit hit and miss. Good luck

 

[Masood]

Might it be worth getting a freeze kit and trying to remove the thermo valves to give them a good clean up?

I can't see how that will work.

You can freeze the pipe into the valve but what about what's on the other side of the valve????? I think the machine you'd need to freeze a full radiator probably wouldn't fit through your flat door!

Full draindown is not difficult at all providing you have a working drain off cock, a hosepipe and loads of old towels. A bit trickier in a basement but still doable. Although you might be surprised how reasonable a plumber is compared to replacing warped and bubbled laminate if it gets properly soaked.

 

[Anton]

As a temporary fix, you could try taking the thermostatic heads off the valves, these are usually held on by a large knurled collar. this shouldn't involve water since the valve is in 2 parts, valve and head.
Once removed you'll see a pin in the valve, give it a squirt with wd40 and push down on it with something repeatedly, don't pull or undo anything. The pin should eventually pop up (works better with the heating on to get some heat on it) If it works, I'd suggest leaving the heads off until you replace the valves, because the valves will only stick again. There's no maintenance you can do to them apart from replacing the full valves.

 

[Plumbstar Tom]

As a temporary fix, you could try taking the thermostatic heads off the valves, these are usually held on by a large knurled collar. this shouldn't involve water since the valve is in 2 parts, valve and head.
Once removed you'll see a pin in the valve, give it a squirt with wd40 and push down on it with something repeatedly, don't pull or undo anything. The pin should eventually pop up (works better with the heating on to get some heat on it) If it works, I'd suggest leaving the heads off until you replace the valves, because the valves will only stick again. There's no maintenance you can do to them apart from replacing the full valves.

Agreed, i would take the heads off first to see if the pin is stuck down, then try and free it as above then book a plumber in when you can to replace them

 

[Riley]

Ha ha you're quite right Mas I only meant to freeze the rad tail but forgot to imply that the rad would still need draining. More I think about it more I'm thinking get someone in :smile:

 

[SimonG]

Head off, twiddle pin and hit trv body with something heavy. Temp fix.

Dump pressure, isolate rad at lockshield and swap valve with a towel underneath. Perm fix.

 

[wild nomad]

Yup, agree with all above. Definately worth checking to see if the pin on the TRV is stuck in the down position. However, I had a similar problem in a hotel room I was staying in. Fortunately I had an adjustable with me and took a look. Turned out the TRV was fine, but for some reason the lock shield valve was shut. Opened it and that sorted it.

Moral of the story, check your lock shields on the other side of the rad as well. Make sure they're open and free from gunk. However, you won't really know if they're gunked up unless you drain the system and take them off. Not too many short cuts on this one I'm afraid.

 

[Anton]

[QUOTE "Fortunately I had an adjustable with me and took a look"
It was another 'working holiday' then ?
I hope they knocked it off your bill.

 

[willb5000]

Thanks to all for the advice - sounds like step one is to check the pin. Will see how we get on.

thanks again!

WillyB

 

[kris]

Hi willbe5000 welcomr along mate...... from kris