why do i need to keep bleeding radiator

Postby riversider » Mon Dec 15, 2008 10:10 am

Hello newbie here.

I have a radiator at the far end of the house and i have to bleed the damn thing every few weeks.I have had it off the wall during decoration and hosed the inside down so there is no sludge in the sysytem,also the pipes in the house are microbore (8mm ).Do you think the micro bore is the problem and if it is, is their a solution?I was going to gag back the other radiators but i thought i would ask on here first.What is the difference if any between each valve on the radiator and which one should i gag back,is it simply an in and out to each rad in the system?

I have tried bleeding the rad again this morning but either the valve key is rounded off or the bleed valve itself,arghhhhhhhh i am going to buy a new valve key and try it before i ask the next question of how to get the thing out.

Thanks for any help. :oops:
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Simply Build It

Postby muppet1967 » Mon Dec 15, 2008 7:09 pm

You might have an air leak. As air is a gas, you might have a small leak which is not big enough to leak water but big enough to let in air. As the pump pumps the water round the system, the water coming out of the pump is being pushed around, how ever the water coming into the pump is actually being sucked into the pump. If theres a leak on the inlet side of the pump, the pump could be drawing the air in. To check you'll have to drain the system and pressurise the system. You then use leak detection fluid to find the leak. A lot of messing about. The bleed valve needs to be totally unscrewed.
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Postby riversider » Tue Dec 16, 2008 9:32 am

hi muppet,

I know how to drain the system but i dont know how to pressurise it,is there a step by step procedure anywhere.
Does it make a difference to the temp of the radiator when you use thermostatic valve types (on max) opposed to the old type.Another of my rads at the same far end of the house has decided to get cold,this rad as well as the other as above was also an addition when i got an extension built.

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Postby DOCTOR BOB » Tue Dec 16, 2008 10:30 am

It sounds a bit like a build up of hydrogen gas. This can be tested by trying to light the air coming from the bleed valve but be careful!. This gas build up can be caused by the water pump being to strong for the size of the pipes feeding the radiators and also not enough "inhibitor" in the system. I would first try putting an "inhibitor" into the heating system. This should work.
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Postby SweetBriar » Tue Dec 30, 2008 8:42 pm

Sorry, taking one radiator off and hosing it out will not remove all the sludge from your heating sytem..... :(
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Postby TheDoctor5 » Thu Jan 29, 2009 12:29 pm

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