Cold Radiators in Loft

[Steven Gonzalez]

Hi,


I'm having some problems getting the radiators in my loft to come on. I recently moved here and have never used them


One of them heats up very rarely only and along the bottom so I tried to bleed it. A small amount of air came out but nothing more so I went to increase the pressure using the mains feed at the boiler and noticed there is no pressure gauge, only something called a "flowmasta".


Can anyone tell me whether I do need more pressure based on this description? Or what this "flowmasta" does and if it replaces my pressure gauge?


Thanks for any help.

 

[steadyon]

The "Flomasta" device is the circulating pump, and is nothing to do with system pressure.

Assuming you have a sealed system, you need to find the filling loop. This is (normally) a braided pipe connecting the return pipe form the boiler to the mains cold water pipe. Attached to the solid pipework at each end of the braided hose there should be an isolating valve, and at the boiler return pipe end there should also be a check valve. The water regulations call for the braided hose to be removed once the boiler has been pressurised, but it rarely is. You should also be able to find an expansion vessel (usually a roundish, red metal canister), which should have a pressure gauge on it. This is usually near the filling loop.

To re-pressurise:

a. System off and cold.
b. Open valve at boiler return end of filling loop.
c. Open valve at mains water end of filling loop.
d. Watch pressure gauge. When normal pressure (between 1.0 and 1.5 bar) is reached close loop by shutting off both valves.

You will then need to bleed your loft radiator, and as you do, the pressure on the gauge will reduce. When water, not air, comes out of radiator, re-pressurise boiler to normal working pressure, as above.

 

[jtsplumbing]

What's the silver braided pipe on right of first photo, another photo of this area please

 

[village idiot]

I can tell you without seeing the said silver braided pipe jts is refering to that: Your system is not pressurised and the radiator(s) you are refering to are higher than the feed & expansion tank feeding your system. Which is why not much air or water came off the radiator when you bled it. If it was just a pressure issue, the boiler will not fire for lack of pressure.

 

[stevetheplumber]

I can tell you without seeing the said silver braided pipe jts is refering to that: Your system is not pressurised and the radiator(s) you are refering to are higher than the feed & expansion tank feeding your system. Which is why not much air or water came off the radiator when you bled it. If it was just a pressure issue, the boiler will not fire for lack of pressure.

how do you come to that conclusion?loop could be anywhere on system. Not even sure thats a pump does the OP have a better picture of the flowmaster and also one of the whole set up taken from further back

 

[village idiot]

how do you come to that conclusion?loop could be anywhere on system. Not even sure thats a pump does the OP have a better picture of the flowmaster and also one of the whole set up taken from further back

This is how I know: One of them heats up very rarely only and along the bottom so I tried to bleed it. A small amount of air came out but nothing more Surely, you are not suggesting that the OP just cracked open the bleed nipple then turned it back off? OP has tried blleding the said radiator but: 'a small amount of air came out and nothing more'. He would have been asking us how to top up his boiler pressure as he now has no heating/hot water. Also. OP says radiator only heats at bottom. Ofcourse, it does as that is the only section occupied by water.

 

[jtsplumbing]

This is how I know: One of them heats up very rarely only and along the bottom so I tried to bleed it. A small amount of air came out but nothing more Surely, you are not suggesting that the OP just cracked open the bleed nipple then turned it back off? OP has tried blleding the said radiator but: 'a small amount of air came out and nothing more'. He would have been asking us how to top up his boiler pressure as he now has no heating/hot water. Also. OP says radiator only heats at bottom. Ofcourse, it does as that is the only section occupied by water.

OP says he went to increase pressure using mains feed, but could not find gauge, rads are empty and need toping up via filling loop, that will be wherever expansion vessel is , Proberly in cupboard in loft, Flomasta is the pump , OP needs to look round for red expansion vessel.

 

[village idiot]

OP says he went to increase pressure using mains feed, but could not find gauge, rads are empty and need toping up via filling loop, that will be wherever expansion vessel is , Proberly in cupboard in loft, Flomasta is the pump , OP needs to look round for red expansion vessel.

If OP went to increase pressure (after bleeding a radiator), then the system pressure would have decreased and boiler would not respond to a demand for heating or hot water

 

[jtsplumbing]

If OP went to increase pressure (after bleeding a radiator), then the system pressure would have decreased and boiler would not respond to a demand for heating or hot water

Its a heat only boiler open vent or sealed system, not fitted with low pressure cut off.

 

[village idiot]

Its a heat only boiler open vent or sealed system, not fitted with low pressure cut off.

OK point taken

 

[stevetheplumber]

probably find its open vent and the ball valve is frozen up or turned off it hink the OP was looking for a filler and couldnt find one it could even be theres no ballvalve in the header tank and he needs to fill it manually reasoning is servo warm used to use flowmaster stuff

 

[village idiot]

It is still my opinion that it is an open vent system and the radiator is higher than the f&e. I'ii bow out

 

[buckley plumb]

It is still my opinion that it is an open vent system and the radiator is higher than the f&e. I'ii bow out

Seen that mate. Place I used to work guy put high towel rail on which top 10 inches were higher than cistern in airing cupboard and he wondered why he could not bleed it

 

[jtsplumbing]

Flomasta 'A' Rated Pumps available from screwfix, Still believe it's a sealed system more information from OP would be useful

 

[Sparkgap]

Is there a pressure gauge somewhere on the system you could check?