Low rad pressure upstairs

Banbh

I'm having trouble bleeding the upstairs rads as there is no pressure in the system. Is this because the supply tank is not high enough?

I was thinking of either replacing the rads (three of them) with low ones or raising the supply tank.

Any advice?

scudo2

Banbh wrote: »

I'm having trouble bleeding the upstairs rads as there is no pressure in the system. Is this because the supply tank is not high enough?

I was thinking of either replacing the rads (three of them) with low ones or raising the supply tank.

Any advice?

Check that there is water in supply tank firstly . Once water level is above radiators they will fill. Water finds its own level in a heating system.

Robbie.G

Banbh wrote: »

I'm having trouble bleeding the upstairs rads as there is no pressure in the system. Is this because the supply tank is not high enough?

I was thinking of either replacing the rads (three of them) with low ones or raising the supply tank.

Any advice?

There is no need to change rads.Is your supply tank higher or lower than the rads.
It's more than likely a water problem either an airlock in the cold feed or ball valve stuck.Check that there is water in the tank

Banbh

Thanks (I nearly typed tanks). There is very little height between the tank and the rads - about a foot as best as I can estimate. I'm just getting the system up and running again after the summer but last winter I had to bleed these rads almost daily and it takes ages. When I opened one valve it actually started sucking air.
I'll check the water supply today - it's very inaccessible due to an attic conversion.

PS: radiator key won't work on one. I hope this doesn't mean having to take off the rad and drill out the valve.

scudo2

Banbh wrote: »

Thanks (I nearly typed tanks). There is very little height between the tank and the rads - about a foot as best as I can estimate. I'm just getting the system up and running again after the summer but last winter I had to bleed these rads almost daily and it takes ages. When I opened one valve it actually started sucking air.
I'll check the water supply today - it's very inaccessible due to an attic conversion.

PS: radiator key won't work on one. I hope this doesn't mean having to take off the rad and drill out the valve.

It might be best to call in a plumber as you have an underlying problem if you have to vent the rads daily, two of the normal causes are a water leak but the most likley is the pipe work due to the attic conversion, hot heating water pitching into the tank producing air and rusting Radiators internally.
Also the cause of air locks and sludge.

Plumber can also fit new vent on rad without removing it.

A plumber looking at it could tell you more and give a better opinion by seeing your setup.

What area are you in, and hopefully somebody here can call to help if you don't already know a good plumber.

Banbh

Thanks scudo. I'll check for a leak though I know there is none within the house - the only place their could be one is in the boiler which is outside.

How do you fit a new vent on a rad without removing it? They are always placed on the inside so it is impossible to drill them out.

scudo2

Banbh wrote: »

Thanks scudo. I'll check for a leak though I know there is none within the house - the only place their could be one is in the boiler which is outside.

How do you fit a new vent on a rad without removing it? They are always placed on the inside so it is impossible to drill them out.

Normaly plumbers fit a self tapping screw on the very top + sealant
or drill a hole, re tread it for a new air vent that can be bought in plumbing supplys. Not an easy DIY job without stocks and dies for retreading 10mm hole.

Banbh

Might be a job for the professional all right. It wouldn't do if the vent blew out in the middle of a cold night.