Radiators Help and information on all topics relating to your central heating, air conditioning and ventilation issues.

[DIPPY]

I have to bleed my radiators every day - why? They are all thermostatically controlled and there is no wall mounted thermostat on my central heating system. The system is approximately 14 years old. Help!!

[Sam]

edit

[DIPPY]

Why would thermometers help when my radiators are full of air? Where does the air come from? :(

It is a vented system with header tank, it is an Ideal Classic boiler powering 16 radiators.

[Sam]

Sorry i sent post to wrong thread.I've edited it now.
You can buy automatic bleed valves to replace the manual ones,these will let the air out automatically if there is any in the rads.

[DIPPY]

Thank you for that Sam, but any idea where air might be coming from? There are no visible leaks anywhere on the radiators so how is air getting in them? :(

[Bay Plumbing]

Dippy,
let us know what type of system you have,F&E (tank in loft) and cylinder in the cupboard or Combi System fed from mains water and no tank.this should help us out


Mark

[coaster]

ime guessing it is open vented system if it was combi then it would cut out due to lack of pressure first thing i would do is change the ball and valve in the makeup tank in the loft it could be sticking thus not filling quick enough but to be letting in that much air in there has to be a leak somewhere if you have voids downstairs sorry but its floorboards up
screwfix do a new product to fix central heating leakes never used it but worth a try my guess is 99.9% new ball and valve in makeup tank

good luck hope this helps

[DIPPY]

Mark - Bay Plumbing

It is a system with a tank in the loft and a cylinder in an upstairs cupboard.


Coaster

The radiators i have to bled are always the ones upstairs. Not sure what you mean by voids downstairs.

The only radiator which is not right downstairs is the one in the dining room which has patchy heat rather than hot at the bottom and cold at the top. Out of the 17 radiators we have i have to bleed four upstairs ones daily. My hubby says the ball cock is ok and is not sticking.

[coaster]

hi

all i can say is the only way air can get into your system is via the header tank in the loft and the only way this can happen is if it keeps topping up frequantly which can only be caused by a leak in the system by voids i mean downstairs is there a space or gap under your floor boards if leak is there then you would never know unless you took you floorboards up are you heating pipes underground or surface mounted try leak seal from screwfix then introduce fernox that will stop air forming in the system there is no other way air can get in the system by the way as a precaution i would change the ball and valve in the header tank in the loft for £3 it is worth a try

regards

andrew

[The Heating Doctor]

Is this a recent problem or has it always been like this? I would not put too much faith in coasters advice.

[DIPPY]

Coaster - thank you for that.


Heating Doctor

We moved into this house in August 2004. The heating has always been the same as long as we've lived here. I said in my original message the system was 14 years old and there were 16 rads, but i was having a bad maths day - the house was only built in 1997 and we have 17 rads!

I keep worrying that by bleeding the rads i will end up not closing one of them off tight enough and we will have a disastrous leak.

[marrtin]

I think you have far more to worry about than the possibility of a leak. The heating system is regarded as a secondary enclosed system and is designed specifically to exclude fresh water containing oxygen from entering the circuit. Air (Oxygen) entering and being circulated will cause extreme corrosion within the system and eventual failure of radiators and pipes. The resulting rust will also cause a build up of black slurry which will at the best reduce hot water flow.

If we assume the header tank is full of water, it may be the system is poorly designed and air is being drawn down the expansion pipe when the pump starts up. If the pump is set at speed 3, try reducing it to 1. This may cause some of the rads to stop getting hot, so may not be a solution, but may stop the air being drawn in.

[The Heating Doctor]

marrtin has suggested exactly what I was thinking, the pump may be installed just after the open vent and is therefor drawing air down the vent. You need to get this checked out for the reasons marrtin has given and it's not good for the gas bill either.

[DIPPY]

Marrtin and The Heating Doctor thank you very much for that i will show my hubby the comments later and let you kniw how we get on.

Diane

[DIPPY]

To Marrtin and the Heating Doctor.

We have now turned the pump down and i no longer have to bleed the radiators everyday! Down side is they don't get as hot as they used to! My hubby has turned boiler up a tad which seems to have made a bit of difference, in the last ten days just had to bleed them once.

Thank you for your help and suggestions.

Diane