Central heating Problem (rad not heating and noisy pump) PLEASE HELP!!

kyleweb

Recently moved into a new house and had no problems with the central heating/hotwater until yesterday.

one of the radiators wasnt heating properly so I tried to bleed it (others were heating fine). However a lot of escaping air came out but no water at the end of it.
A day later none of the radiators were working at all when the heating came on and the pump starting making a horrible whining noise when it switched on.

Immediately turned it off and read about a lot a of forums but cant work out definitive answer.

Think it could be air in the system since I have now read you should turn off the pump before bleeding the radiator as seems like water isnt getting to the pump and since the bearings are water lubricated that is why it is making the horrible noise.
Tried venting the pump (it is a grundfos by the way) by following instructions and opening venting plug on the front but no water came out there as well.

Really cant afford a plumber at the moment but rather not go with any more cold showers

PLEASE HELP ME!

Canucklehead

Hi

Do you know what type of system you have.?
1) Open vented........ you have a small tank in the roof
2) Sealed ...........you have an expansion vessel somewhere (like a red football)
Or is it a combi?

Corgi Guy.

kyleweb

The system is an open one with the small small tank (is actually in a cupboard in the kitchen as we are in a block of flats)

tank all seems to work fine. is full of water and works when you push down the ballcock.

We moved in about 6month ago now and not had any problems what so ever until I tried to bleed the radiator.

Just tried to do the others and all that happens is that air hisses out but no water.

Not sure if the hot water is working as whenever it switches on the pump makes that horrific squeeling noise so didnt like to leave it on in case i did further damage.

Canucklehead

Hi

Blocked cold feed.
Follow the pipe that is about 2" from the bottom of the small tank down to where it tees into the heating system. That will be the point where it's blocked. Just out of interest see if a magnet sticks to it.

Corgi Guy.

kyleweb

good stuff, doesnt sound like the expensive job that I thought it might be...


... now how do i fix it


ps magnet doesnt seem to stick to it, although only had a really weak fridge one to hand

Canucklehead

Hi

Pipework needs cutting out and cleaning/ replacing, how much depends on the extent of the blockage.All this after draining down. The expansion tank will need emptying as well and the supply to it turned off (obviously) or you will have water everywhere when you get to the unblocked bit.
How practical are you?

Corgi Guy.

Ephemera

If the air is hissing out doesn't that mean it's being displaced by something?

kyleweb

not too bad. never really done any plumbing but usually pretty handy with everything else.

Assume should be pretty easy to just cut the copper piping with a hacksaw and then cut a bit the same length. what do I need to seal it with on the joins?

air only hissed out for a few seconds then nothing so does that still mean it is being displaced by something or just remains after the blockage?

Ephemera

aah.. in your original post you said it was a lot of air....! ??

Best of luck sorting it out!

Eph.

totalsolutions

Hey kyleweb hows it going today?
Just read your message. 1. Keep it simple...the rads are connected by copper pipes (non magnetic material as is lead and plastics) in the pipes is water. This water is heated and you may have a water pressure gauge, if so it must not be at 0 (zero), the boiler will overheat rapidly and cutout.
2. Air gets into the system and needs to be bled. Water in a header tank flows to the rad. system keeping it full. Keep bleeding until water escapes. Do this at each rad. Are the rads. taps open at each end?
3. Water flows from the tank to the rad. drainage point.
4. The pump keeps the water flowing around the closed system, it likes water in the pump housing so dont run it for long without water
5. Don't cut any pipes
6. Water flows from the highest point to the lowest. Connect a hose to a drainage point and 'blow' into it to get any air pocket out and move that water. After that try feeding water pressure into the rad.
Keep it simple. It did work and something small has changed. carefully think it through

kyleweb

Thanks, still not working but have been doing as you said and trying to think it through carefully before cutting away any pipes.

totalsolutions wrote: »

Hey kyleweb hows it going today?
Just read your message. 1. Keep it simple...the rads are connected by copper pipes (non magnetic material as is lead and plastics) in the pipes is water. This water is heated and you may have a water pressure gauge, if so it must not be at 0 (zero), the boiler will overheat rapidly and cutout.

do I still have a pressure gauge if it is an open vent system (which i think from reading about it is)?

totalsolutions wrote: »

2. Air gets into the system and needs to be bled. Water in a header tank flows to the rad. system keeping it full. Keep bleeding until water escapes. Do this at each rad. Are the rads. taps open at each end?

seems when I bleed the radiators that air will come out but never followed by any water. I have done this on all of them and yes taps are open full on both ends

totalsolutions wrote: »

3. Water flows from the tank to the rad. drainage point.
4. The pump keeps the water flowing around the closed system, it likes water in the pump housing so dont run it for long without water
5. Don't cut any pipes

read that the pump is lubricated by water flowing through it so def not been running it in case.

totalsolutions wrote: »

6. Water flows from the highest point to the lowest. Connect a hose to a drainage point and 'blow' into it to get any air pocket out and move that water. After that try feeding water pressure into the rad.
Keep it simple. It did work and something small has changed. carefully think it through

Where would a drainage point be?



Edit for ungratefulness: thanks for all your help, really appreciate it everyone! Really cant afford a plumber at the moment so if I dont do it myself is going to be a cold few months!