losing my mind,help please

PHIGRAN

I have a sealed central heating system, i.e no expansion tank in attic. My rads upstairs are hot at bottom but cold at top, have bled them etc, no water or air comes out., got a plumber over, he said its low pressure or an air lock. he said he needed to find a valve to release the air, but he searched high and low, in the attic, in the hot press, under the stairs where the heating nerve centre is, outside where the boiler is and cant find it, he said its very strange but he said there has to be one somewhere, and cant do anything without finding it. does anyone have any idea where else it could be??

Bruthal

Did he turn on the water feed (filling loop) into the system? A rad with air in it will release its air when you open the bleed screw, but the system needs some pressure in it to do this.

If it has none, you need to turn on the filling loop, (usually mains fed) into the system to pressurise it up a little to expel the air in the rads, and to top up with water as the air is forced out.

Check the pressure on the pressure dial at the boiler, with the system off and cold first anyway.

PHIGRAN

he said it has very low pressure. where is the filling loop located, and what does it looks like?? thanks

Qwerty?

Sounds like your plumber has been looking for the feed.

In my last house it was a Red Handled Stopcock, and a Pressure gauge just after it. When you opened the valve, after a short interval the pressure gauge would start to rise. I think you let it get to about 1bar. Then turn off the stopcock and you can now bleed your rads, you may need to add more pressure after bleeding a rad or two.

Cozzie Bhoy

Filling loop is normaly located near the boiler. Its a stainless braided flexible hose about 1' in lenght with a valve fitted on one end. You could also have an auto fill valve which is brass and has a pressure gauge attached. This might need adjustment. Some systems are semi sealed which have a supply from the 40GL tank in the attic with a non return valve fitted. This might also have an isolation valve fitted which could be turned off.

PHIGRAN

but if the isolation valve was turned off, there would not be any heat in the rads?? they are hot at the bottom when system is on.. he said he was looking for a pressure guage but couldnt find one. sorry ment to say and this is the strange bit, the rad in the bathroom is fine, its different to the others, its a towel rad, and he said the other rads(which dont heat up ) are fine i.e no sludge in them

Bruthal

PHIGRAN wrote: »

but if the isolation valve was turned off, there would not be any heat in the rads?? they are hot at the bottom when system is on.. he said he was looking for a pressure guage but couldnt find one. sorry ment to say and this is the strange bit, the rad in the bathroom is fine, its different to the others, its a towel rad, and he said the other rads(which dont heat up ) are fine i.e no sludge in them

The filling loop valve is normally off when the heating is operational. And if its the flexible silver hose as mentioned by cozzie bhoy, it would also be disconnected after filling the system.

So it sounds like your system is short of water, but has just enough to keep the boiler running withhout tripping, and the rads upstairs will be the most likely to have the most air trapped in them.

The filling loop in my house is just a copper pipe in the hot water cylinder press with a gate valve on it.

gdavis

was he actually a plumber at all??? if he did say it was a vent he had to find then he is talking tripe.system may be filled in hot press.connection off heating coil possibly fed from cw storage tank,more than likely a half inch pipe with red handled gate valve and brass non return valve on it

Bruthal

gdavis wrote: »

was he actually a plumber at all??? if he did say it was a vent he had to find then he is talking tripe.

I was thinking that myself. Hard to imagine a plumber leaving without being able to find the filler. Not too hard to setup a temporary filler anyway, to at least bleed and fill.