Air in the system
- Thread starter Roger29
- Start date
It would help a lot if you told us what type of boiler / system you have.
It is an Ideal Standard floor standing boiler about 20/25 years old E Type RS 80N serial no 70128104, servicing 10 radiators, with indirect cylinder and expansion tank in the loft, the boiler has two 28mm pipes and two 22mm pipes coming from it I guess the 22mm is for the heating system ? as the 28mm go to the cylinder. I have recently had a tall radiator put into the bathroom that replaced a towel type hope this helps.
I look forward to your comments.
I look forward to your comments.
Was it drained and refilled?
Was a corrosion inhibitor added on refill?
Was any pipework opened or altered near to the pump? Is there any sign of leakage where the work was done?
When you bleed the highest radiator in the house, does water squirt out forcefully, and is it hot all over?
Go up into the loft and see if water is being pumped up the vent pipe (which bends over the Feed & Expansion tank) when the pump is running. While you are up there, see how deep the water in the F&E is, and if there is a layer of mud at the bottom of it.
It was not drained completely when the new rad was fitted and no additive was added at that time.
No pipe work was altered near the pump.
the bathroom is now the highest rad and water does come out, it is hot all over however when the system comes on in the morning that rad does not heat up and I have noticed that when it is off as now the rad is now hot!
Have been in the loft the tank is clean and I can see no sing off the over flow having water coming out but certainly the system fill pipe has had water come back up which then overflowed, this happens when the boiler first starts.
The depth of water when cold is 3 3/4 ins and the distance from the bottom of the tank to the overflow is 5 1/2 ins.
Does this help?
No pipe work was altered near the pump.
the bathroom is now the highest rad and water does come out, it is hot all over however when the system comes on in the morning that rad does not heat up and I have noticed that when it is off as now the rad is now hot!
Have been in the loft the tank is clean and I can see no sing off the over flow having water coming out but certainly the system fill pipe has had water come back up which then overflowed, this happens when the boiler first starts.
The depth of water when cold is 3 3/4 ins and the distance from the bottom of the tank to the overflow is 5 1/2 ins.
Does this help?
It should not overflow.
You mean it rose to the top of the F&E and came out of the overflow pipe which goes out of the eaves or somewhere? Have a look at the pump and see what speed it is set to (they usually have speeds 1, 2, 3)
If a corrosion inhibitor chemical was not added, then you will get a certain amount of corrosion of the steel parts mostly. If you can safely hold a flame in front of the bleed valve when you release the gas, you can see if it burns. If so it is hydrogen caused by corrosion. Make sure furniture, curtains, skin etc are out of the way.
You can get Sentinel X100 Corrosion Inhibitor at any DIY shed or Plumbers Merchant for £15 and it will prevent future corrosion unless you have a fault leading to fresh water and/or air getting into the system.
It might be the overflow is caused by expansion of gas (which expands more than water).
The F&E pipe does not appear to be blocked with corrosion sediment, which is good. An old system usually contains a lot of black sludge which interferes with proper circulation, you can loosen this with X400 and drain it out after 4 weeks. It is much easier and cheaper to do this before a blockage occurs.
You mention the bathroom radiator getting hot at odd times. Tinker with the timer and see if you can identify if it is coming on with the HW setting rather than the CH setting. This is not unusual for bathroom towel rails, as it means they get warm in summer when the rest of the heating is off. This is OK but for economy a Thermostatic Radiator Valve should be fitted..
I am just a householder.
How high is the cold level above the bottom outlet? At the moment there is only 1 3/4 inches available from the cold level to the overflow, which may not be enough. There needs to be enough room between the cold level and the overflow to allow for the expansion of the water when it heats up - you have to allow 4% of the system volume. As this problem has only happened after you installed a new towel rad, it could mean that the system volume has increased enough to make the water expand above the overflow.
You can lower the cold level by bailing some water out. The important thing is that the float valve must open before the level goes below the outlet to the tank; if it doesn't open, air will get into the system. You can adjust the float by bending the arm or adjusting a screw.
The distance between the top of the out let and the bottom of the overflow is 3 1/2 ins.
I think you are correct re the capacity of the system as in fact there has been two extra rads fitted the other was fitted some 18 months ago with no apparent change but now with this new one I guess it has pushed it over the top, do you think?
Are you suggesting I raise the overflow pipe? if I do this would it be best to raise the ball valve also?
I think you are correct re the capacity of the system as in fact there has been two extra rads fitted the other was fitted some 18 months ago with no apparent change but now with this new one I guess it has pushed it over the top, do you think?
Are you suggesting I raise the overflow pipe? if I do this would it be best to raise the ball valve also?
No. The first thing to do is to get the water level correct; it is too high. Let the water go cold and then bail some out with a jug etc so the ball drops and the valve opens. This should happen when the level is about half an inch above the outlet. If it is any higher, adjust the ball valve (bend the arm down or whatever method is appropriate.) and retest. This will increase the space available from 1 3/4 inches to 3 inches, which may be enough. If it is not, you will have to install a larger F/E tank or raise the overflow level.
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