Central Heating Problem

barfletcher

Hi all,

I have oil central heating in a new house which has been working fine until last week. first 2 radiators upstairs were cold so I tried bleeding them but there was no air inside when I opened the bleed valves. Now the problem has spread and most radiators upstairs are not heating but 2 or 3 are?

As I say not all upstairs radiators are cold only some and all ground floor ones are fine??

Any ideas please?

crosstownk

First of all do you have a sealed system? If you do, you may have low pressure due to bleeding the rads which releases pressure. Check near the boiler for a pressure guage and see what it reads - it should read around 1bar when the system is cold.

O7Pat

barfletcher wrote: »

Hi all,

I have oil central heating in a new house which has been working fine until last week. first 2 radiators upstairs were cold so I tried bleeding them but there was no air inside when I opened the bleed valves. Now the problem has spread and most radiators upstairs are not heating but 2 or 3 are?

As I say not all upstairs radiators are cold only some and all ground floor ones are fine??

Any ideas please?

This happened me once and the solution was somebody had turned off the "pump" switch on the heating system (near the timer on mine) so only the downstairs rads were working correctly. I have sperate switches also for upstairs and down and i think this is why the pump switch needed to be on.

barfletcher

Thanks lads, and sorry for the slow response, just got Broadband setup yesterday evening..........

I dont have a pump switch (to my knowledge). A friend suggested turning off all the downstairs rads and that worked, the rads upstairs (with the exception of 2) all heated up. Now that I've turned on the downstairs ones again, upstairs have gone off (not all of them mind just some?)

The inlet pipes on the 4 not working are cold also??

Barry

crosstownk

It sounds like either low pressure or a faulty pump. Check the pressure first - there should be a gauge close to the boiler - sometimes it's hidden behind the boiler's front panel.

barfletcher

Will check that out.

One thing, I have 2 rads almost side by side. One is hot, on the other, the supply pipe is hot but the rad is cold, when I open the bleed valve, nothing, no air or water?

barfletcher

Just checked and there is no pressure on the meter (almost at 0) How do I fix that???

crosstownk

You need to locate the filler valve. The location of this varies, but attic & hot press are good starters. Once you locate it, open it briefly and close it again, then recheck the pressure guage - if it rises then you have the right valve. Open it until the pressure reaches 1 bar when the system is cold. It's better to open and close regularly rather than over pressurising the system. Once you get the pressure right then fire up the boiler. Check all you rads as you may need to bleed them. Remember that every time you bleed you open the system and reduce the pressure somewhat - so always keep an eye on the guage.

barfletcher

Thanks - will try that when I get home this evening.

I seem to have 2 valves. There is one "Black" valve then a pressure gauge and then another valve which to me looks closed?

I have a pic here if you wouldn't mind taking a look for me?

http://img72.imageshack.us/my.php?image=img00096vc7.jpg

CDfm

Im not a plumber but here is a tip I got from my guy on these problems for a gas system and works for both oil and gas...

When you have a system shut of for the winter etc valves can stick. Valves are made of a condom type substance so they can perish so dont always bounce back.

So you may have an air lock somewhere in your piping that is being bypassed by the water supply.

So turn of all the boiler and turn the temperature valves on each rad off ie no hot water will flow thru that radiator. So if the airlock Is radiator specific or the valve is just stuck it will kick start it and you just bleed it and it should work.

IF there are multiple airlocks- turn all the rads off. Then -starting at 1 rad turn it on - bleed it - turn it off and on to the next. By the time you get to the last you will have no air in your system.

Ive never understood my gas system so qwill be checking my pressure later -

gavdbyrne

Hi I have a similiar problem in my new apartment. All of my rads were cold when I used my central heating for the first few times. Over the last few weeks I've bled the rads and topped up the pressure so it's at 1 bar a few times. Now 2 of my rads heat up but the rest are stone cold, including the inlet pipes.

CDfm, will try your suggestion. So with all the radiators set to off, do I then start up the central heating and do the one by one turning on and bleeding?

Any other ideas, I assume as two of them are working that it's a case of airlocks etc just because they are getting used for the first time in a new apartment?

CDfm

gavdbyrne wrote: »

Hi I have a similiar problem in my new apartment. All of my rads were cold when I used my central heating for the first few times. Over the last few weeks I've bled the rads and topped up the pressure so it's at 1 bar a few times. Now 2 of my rads heat up but the rest are stone cold, including the inlet pipes.

CDfm, will try your suggestion. So with all the radiators set to off, do I then start up the central heating and do the one by one turning on and bleeding?

Any other ideas, I assume as two of them are working that it's a case of airlocks etc just because they are getting used for the first time in a new apartment?

ya start with all the rads off then do the first one beside the boiler.

that done - turn it off turn the next one on etc.

the reason is that the sytem finds a way to bypass radiators around the airbllock

what you are trying to do is shift the airblock and bleed it out via the radiators

you are also trying to force open the valve diaphrams if they are the source of the problem

thus at the end you should have no airlocks and will know if its a pump or valve problem

or if it works

gavdbyrne

Thanks, will give that a go