Upstairs rads cold, downstairs hot - need advice for fixing

QueensGael

Hi all,

I searched for forum for related threads, but didn't find anything that quite answered this, so apologies in advance if this question has been done to death somewhere else... Here's the scenario and I'm hoping you can help me with what I need to do next.

I have gas-fired heating, fairly bog standard 1970's type radiators and no zoning AFAIK. The heating system worked fine last year. It has a timer and manual switch (I use the manual switch), and doesn't run off a stove or anything similar.

I had the boiler serviced about a month ago. When I turn on the heating switch, the downstairs rads (4 of them) heat up as normal, but the upstairs ones (also 4) are stone cold. I tried bleeding all the rads: in the downstairs ones, water comes out, but upstairs, I get the faintest hiss in one of them, and nothing in the others. The pipes going into the rads are also cold in the upstairs rads.

I've tried a few combinations:

• downstairs rads open, upstairs rads open -> downstairs hot, upstairs cold
• downstairs rads closed, upstairs rads open -> all rads cold
• In all cases, the hot water in the taps was running upstairs and downstairs

There isn't any sound out of the upstairs rads, no clanging or the sound of water flowing (which it used to do last winter). I checked the gauge after the heating was running for 2 hours, and it didn't seem to have any pressure in it (see attached).

So my question is -

• Is this a pump problem?
• Is is something I can fix myself? (I can do fairly basic repairs)
• If not, should I go back to the guy who did the boiler service, or does it need a plumber?

Thanks in advance for your help!

shane0007

You have no pressure in your system, so basically the water has emptied out of the upstairs circuit and there is only water in the downstairs circuit. The faint hissing is the lack of pressure to refill the radiators. You need to find the filling loop or the filling valve and bring the pressure back to between 1 and 1.5 bar on the gauge and then switch off the fill valve. bleed all the radiators and open the bleed screw on the air vent to the left of the pressure gauge. You may have to open the valve a couple of times to bring the pressure back to 1 - 1.5 bar.

You most likely have a leak, weep or expansion vessel failure on the system as you have lost a decent amount of water from the system and it has gone somewhere.

Your service guy should have checked the system pressure as part of the service but the problem may have arisen since he was there.

QueensGael

Thanks shane0007, I'll try it out this evening

QueensGael

Just to follow up - there was no water in the upstairs rads, as the tank in the attic ran dry and the ballcock wasn't positioned correctly to automatically fill up. All is working fine now, thanks for your help!

shane0007

I would also be asking where did the water go from your system? There must be a leak somewhere to loose that amount of water.