We recently bought a house, and we’re not sure whether the boiler has a problem. This is a UK style condensing boiler, by the way.
Well, after bleeding the radiators some week ago the pressure gauge on the boiler’s front went lower and lower, until it was hovering around zero - rising up a bit (half a bar or less) when the boiler was in operation - for example when the heating was on.
“Easy”, I thought, after going through the manual and checking online, “I just have to refill it with water to compensate for the lost pressure due to the air bleeding”. So I did. It was indeed easy. Stick a special key in a socket at the bottom of the boiler, turn, open a little plastic tap, let the water in, watch the pressure gauge. And stop when the pressure goes back to its indented value.
Well, the problem now is that the pressure keeps going down to zero. I must have refilled the boiler about ten times, but in a few days it goes down again. There are no visible damp patches that indicate a leaky pipe. Also, some heating elements in the house don’t get warm at all.
What can I check, and is it worth it to call in a plumber?
And since I am around asking opinions, is a power flush something useful or necessary? The biggest proponents of power flushes are those that do them, and usually charge quite a bit of money.
Sounds to me like you have a leak somewhere, but I’m not familiar with condensing boilers. A system flush could clean out enough scale to make a leak evident.
You need to get it checked - the leak could be anywhere and you might not notice until some serious damage is done. My BiL had a pinhole leak in the back of an enclosed radiator behind a sofa - then they finally figured it out, the plaster behind and carpets under the sofa were ruined. Covered by insurance, but it really was a mess.
I wouldn’t have a powerflush - I think there is too much risk of damaging something somewhere expensive.
Si
I’m so glad this is not a medical question after all. :eek:
Is there an organ of the human body called “boiler” that I did not learn about in Biology classes?
Maybe I was thinking of boils. Or maybe I have a sick need to make inappropriate jokes.
you need the refill valve open when you do the bleeding. you want to finish bleeding at the highest point in each heating loop.
No, but I suspect my thoughts at first reading “power flushing” were similar to Ellen Scary’s! :eek:
Is it an older Worcester boiler> sounds like it could be, what with the key you need to put in.
In any event the first thing to do is to check the pressure relief pipework. Go outside and see where the flue gases go out. Somewhere below that (usually) there will be a 15mm (1/2") copper pipe. that is the outlet for the pressure relief valve. Put the system back up to pressure and then check the pipeoutside to see if any water is coming out of that - it should be completely dry. If it’s not then you will need to get a boiler guy in (unless you are a very competent DIY’er).
If its not that then you have a leadk somewhere in the system. if you can’t see it then it could be within a pipe that is buried underneath the ground floor.
it is possible to put some leak sealer in it but really it might not be a good idea. That depends upon the model and make of your boiler and a few othre things.
As far as the powerflush goes, Full disclosure I am a powerflush specialist. (Also an ex-Gase Safe/CORGI engineer too)
I have done over 1000 powerflushes and have uncovered leaks on two occasions - both times they were pinhole leaks on rads which can go at any time - and both could be sorted whilst a plumber was there. Powerflushing can work wonders for problem systems, but, unless you have any of the common problems/symptoms of muck in the system then there is no need to have a powerflush.
For more advice do feel free to give me a call. I try to be as unbiased as possible and in truth, no offence, but I am busy enough that whether you use my service or not does not make a blind bit of difference to me. www.pritchard-heating.co.uk
Hope that helps.
all the best, Ian
Yup, it is indeed an old Worcester boiler. It’s a 24CDI. I reckon it’s about 10-12 years old, but I could be wrong.
I’ll have a go tomorrow at checking the pipe for the pressure release valve, thanks for the advice! I live in Newcastle and it looks like you’re based near Bristol from your website, so it might be too far for you anyway.
You mention about common symptoms that indicate a power flush is needed, what should I look out for? Also, why did all this problem start after bleeding the air out? The pressure was OK before doing that.