Central Heating not working (sooo cold) :-(

[Jdubs]

Hi all,


I have spent the morning googling and searching this forum for the answers to my problems, rather than high jack another similar thread (which does not help me) I thought best to post up fresh.

I have a block in my central heating some where which means that the boiler starts and then stops.

I had the same issue before which cost a fortune for a plumber to come out and try to clear the blockage by backfilling, this solved the problem, in that the heating worked but it did not clear the blockage (mains did not rush into the header tank)

Another issue is that the timer only works if it is in factory set mode (timer setting after reset) so I am not able to adjust the ch or hw timing to suite, if I do change them then nothing happens at all!

I also bled the radiators this morning and since then the boiler won't work, I don't understand where the water went, if the plumber back filled the system so essentially the system was full again and now it's not where is the water going? It's almost as if there is no water in the system at all instead of a block!

I've opened the thumb wheels on the bleed pipes in the loft but nothing happened, no air, no water. I've also checked the radiators again in on some of them I can take the bleed screw out and barely any water comes out in other the water rushes out.

Can anybody put these symptoms together an come up with a long term fix? I'm pretty handy at this sort of stuff and really can't afford to get anyone in. Perhaps if someone can explain how to backfill the system this will at least get my heating going again and get me through Christmas..

Thanks James

 

[Armo74]

Check the water level in your feed and expansion tank, Check for a blockage with a magnet where your cold feed tee's into your flow pipe from your boiler.

 

[Burnerman]

Paragraph 3 - you say that water isn't rushing into the header tank?
This is mains fed, through the ball valve. Is the valve stuck in the up position? The header tank needs around 4" of water in it to keep the system happy, and without this there will be all sorts of problems.
Can you sort that first?
John

 

[Jdubs]

Paragraph 3 - you say that water isn't rushing into the header tank?
This is mains fed, through the ball valve. Is the valve stuck in the up position? The header tank needs around 4" of water in it to keep the system happy, and without this there will be all sorts of problems.
Can you sort that first?
John

When the plumber back filled the system he said that if te blockage had cleared then while he was backfilling the water would have rushed into the header tank and quickly filled it up, it didn't so blockage wasn't cleared.

The expansion tank does have water in it.

 

[Jdubs]

Check the water level in your feed and expansion tank, Check for a blockage with a magnet where your cold feed tee's into your flow pipe from your boiler.

Feed and expansion tank = header tank?

I have used a fridge magnet along the whole pipe and it picked up nothing.

 

[Burnerman]

There are some real issues here, aren't there....
Back filling the system (unorthodox but it does work) is fine, but it doesn't explain why mains water doesn't fill up the expansion tank (header tank) on its own.
I think I'd be removing one radiator completely, and then opening one valve at a time to see if you can get some flow. Bleeding the rad doesn't really tell you too much, as the rad can be filled from either the flow or return.
John

 

[Jdubs]

To give you a bit more info.

The pump started making a loud noise and the plumber said it was on its way out so replaced it, after he did this the central heating showed the same symptoms it is now and did not work, so I called another plumber out who fixed a few issues with the boiler and then back filled the system and it worked but now it's started again, could this be because I bled the radiotors? Some of them took a very long time to stop hissing a few minutes in some cases.

Water that came out was clear though (where it did come out)

 

[Jdubs]

There are some real issues here, aren't there....
Back filling the system (unorthodox but it does work) is fine, but it doesn't explain why mains water doesn't fill up the expansion tank (header tank) on its own.
I think I'd be removing one radiator completely, and then opening one valve at a time to see if you can get some flow. Bleeding the rad doesn't really tell you too much, as the rad can be filled from either the flow or return.
John

Is there an order in which I need to open these valves? Can I isolate a rad before removing it or do I need to drain down the whole system?

 

[Burnerman]

Pumps usually start complaining if they are trying to pump air rather than water......this isn't to say that the pump wasn't faulty though.
If your rad of choice has ordinary valves - and not a TRV on one end, then turning them both off will allow the rad to be disconnected and removed.
Opening either valve one at a time should allow a gush of water.....if the water does start to flow the chances are it will be very black, so watch the carpet!
As you allow water out of the system, the header tank valve should open, allowing fresh water in.
John

 

[Jdubs]

Pumps usually start complaining if they are trying to pump air rather than water......this isn't to say that the pump wasn't faulty though.
If your rad of choice has ordinary valves - and not a TRV on one end, then turning them both off will allow the rad to be disconnected and removed.
Opening either valve one at a time should allow a gush of water.....if the water does start to flow the chances are it will be very black, so watch the carpet!
As you allow water out of the system, the header tank valve should open, allowing fresh water in.
John

I have the radiator off the wall, I'm not sure how in going to open up each valve and tackle the water coming out and check the header tank to see if the mains is filling it at the same time, any tips? Thanks

 

[Jdubs]

Ignore my last comment I turned it on slightly and let it trickle into a washing up bowl, anyway in both cases the water slowed and ten stoped, does this mean there is no water in my system?

 

[twgas]

your cold feed is almost certainly blocked, possibly the pipes around it are also blocked.
Back-filling will not cure your problems, it might get some heat on but if your blockages are as bad as it sounds I would advise against using it.

 

[Jdubs]

After taking a radiator off the wall and finding no water in the system (but fe tank was full) I took a magnet along the 15mm pipe and found that where it joins the 22mm pipe it had a u shaped bending in the pipe which feed into the bottom of the 22mm pipe, which runs to the boiler. I couldn't understand why they would put it in like that! Makes Sense that that's where the blockage is going to occur. So I took the 15mm pipe out completely and flushed it out (loads of crap!!), I also cut into the 22mm pipe to make sure it wasn't blocked further and changed the fitting by blocking off the old t junction, fitting a new one and changing the angle. I also pulled the header tank out the loft and have it a very good clean!

After lots of bleeding from the pipes in the loft I got the heating working after about 13 hrs of working on it and its running fine!

Thanks Burnerman!!

Now I do still have the issue with the timer, any ideas?