CH - Downstairs Rads get hot Randomly

[kingandi]

Hi guys,

I've got a problem with my CH. It doesn't help that I'm a new to a wet heating system - in the past it's been Economy 7 all the way!

I've recently changed my old TRV's for new as I found that a couple weren't working properly. However, now the radiators downstairs either don't get hot at all, or some do and others don't. The problem is that it's not the same radiators each time!

I've managed to get the all the downstairs rads come on together 3 times in a row.

I've turned the upstairs rads off to try and force the water through downstairs, but this doesn't seem to make a difference. I seem to have some success getting the water to circulate by 'shocking' the system by turning rads off then back on, but it's not an ideal solution.

Anyone got any ideas?

Thanks!!

 

[D_Hailsham]

Did you balance the system after you replaced all the TRVs?

 

[kingandi]

Yeah - closed everything down and opened them up so that each upstairs rad was achieving temperature - unless I'm getting something wrong?

 

[D_Hailsham]

Yeah - closed everything down and opened them up so that each upstairs rad was achieving temperature - unless I'm getting something wrong?

Presumably you opened fully all the lockshield valves?! If so, that's where you went wrong.

Read How to balance a CH system.

 

[kingandi]

Thanks - I'm pretty sure I did that in the beginning, but frustration kicked in a while ago and will try again to make sure. It's the fact that sometimes it works and sometimes it doesn't!

I had the CH on all night, all the rads were running, and yet when the HW started up on the program this morning, the rads lost temperature. I suspect the motorised valve (Honeywell V4073) isn't working properly - there's no resistance in the lever and I have it in the 'manual' position. Is there any way to check?

 

[D_Hailsham]

I suspect the motorised valve (Honeywell V4073) isn't working properly - there's no resistance in the lever and I have it in the 'manual' position. Is there any way to check?

See How a mid-position valve works for fault finding info.