lots of problems with my central heating

[powerjoanne]

Hi wondering if anyone can give me some advice. Every now and again the pressure in my combi boiler drops and I have to keep topping it up to build the pressure up again. I do live in a fairly big house. A friend of mine who is a plumber told me that this can be quite normal and just to keep topping it up. Having said that he said that there may also be a leak which may be a reason as to why the pressure keeps dropping all the time. He did check all the radiators and said that as far as he could tell he couldnt find a leak but that there could be one under the floor boards. He said that this was unlikely as i would probably see a leak in the celling or on the floor so he said it prob just a case or keep topping up the pressure. I have only just started to put the heating on and i have just noticed that some of the radiators as hot at the top but cold at the bottom. I have read that this could mean sludge and that the system may need to be cleaned out but could the contining drop in pressure be anything to do with it as well? I am having to top up the pressure at the moment every 2-4 weeks. any help woule be much appreciated
kind regards a very worried lady

 

[doitall]

Keep topping it up at your peril, as it will corrode the system out, so no, it isn't normal, allbeit common.

What does the pressure go up to when the boilers on.

Is there a remote expansion vessel anywhere.

Should ask what the make and model of the boiler is, and how old.

 

[powerjoanne]

it is a worchester combi boiler i think about 10 yrs old
i top the pressure up to 1.2. It maybe rises by 0.2 when it comes on? it doesnt go up by much!
unforunately i dont know what an remote expansion vessel is?!

 

[doitall]

Did your plumber check if the Pressure relief pipe is dripping.

Check all the radiator valves for signs of water, when the system is cold, you can take the valve heads off to check the glands.

 

[davebgas]

How many radiators do you have out of interest?

 

[powerjoanne]

I have about 13 radiators. I have noticed a lot of steam sometimes coming from its over pressure valve?! I think that is what u call it. When the pressure drops to 0 I have been topping the pressure up to 1.2 bar but when the healing comes on the pressure shoots up to over 3 bar.

 

[glasgowgas]

see wiki at top of page for details on how to recharge your boilers expansion vessel

 

[bengasman]

System full of gunk, needs cleaning thoroughly.
Gunk/lack of flow/dying pump cause boiler to overheat, hence the steam and sudden pressure rise.
Seems like the overheat stat is not working properly, this needs sorting asap, and prv probably failing, needs replacing.
Gunk in system has knackered aav, needs replacing.
500 - 600 quid should do the job.

 

[darren17]

there is dirt in the system and when you contuine to top up the system with water you are bringing oxygenated water into the system which is the cause of the dirt which in turn builds up thats why you get cold spots.
as for the prv if it is leaking give it a turn
if that doese'nt stop it then replace.
as for cleaning the system get yourself 2 lts of fernox heavy duty restorer
also it would be a good idea to install a fernox tf1 magnetic / non- magnetic filter.
you should be using a gas safe engineer to comply with reg's
the system should be pressurised to about 1.5 bar and the disconnect the filling loop.