Radiators Cold -All except 1

[bom1304]

Hi, Please help.

All our radiators are cold except our bedroom radiator which is hot (closest ?). This was a gradual process with the living room (furthest ?) stopping working first. This has gradually happened over a preiod of a few months, we have just been too busy to look at the problem.

Yesterday we drained each radiator (using the drain nipple on eah one) then bleed the radiators, downstairs 1st then upstairs (we had the central heating on at this point, don't know if thats correct). As the radiators refilled they were hot, but then cooled down as we moved on to the next radiator.

We then attempted to balance the system by turning them all on full blast (our bedroom radiator was the oly one working) and the turning the valve down about 75% on the bedroom radiator, but nothing happened.

We don't think its the pump, you can hear it humming quietly and if you put your hand on it you can feel the vibration, but we hit it gently a few times to make sure it wasn't stuck.

We have checked the ball cock in the loft and that seems to be okay.

Problem could be the timer in the kitchen, for a couple of years now we haven't been able to have the water and heating at the same time, it trips out. The model is Danfoss CP15, so we know we need to replace this.

Central heating system is 9 years old.

If you can offer any advice we would be so grateful, we simply have not got the money to call in a plumber.

Regards

Bom1304

 

[breezer]

see this

 

[bom1304]

1)Boiler make / model (gas or oil)
Gas - Glow Worm Ultimate

2) What is / is not happening
Bedroom radiator working, bathroom radiator luke warm, rest of house cold. We have hot water.

3) Has ANYTHING else been done / changed recently
Yesterday we drained radiators, bleed (with system on - is this correct), attempted to balance.

4) When did it (problem) start
Living room radiator hasn't worked for approximately 2 years, followed gradualy by other radiators in house.

5) When does it happen? eg, heating coming on or going off

6) Anything else you feel may be of relevance
-Timer in Kitchen - Danfoss CP15 - if you try and put water and heating on it clicks off.
-If you flick the immersion on from switch in airing cupboard the electricity trips off.
-We have hot water when we have had the heating on

Hope this helps. Thanks

 

[IanDB]

If you flick the immersion on from switch in airing cupboard the electricity trips off.

The insulation on your immersion heater has broken down. It needs to be replaced.

Yesterday we drained radiators, bleed (with system on - is this correct),

You should have the heating off when you bleed the radiators as there is a possibility that air will get drawn into the system.

Bedroom radiator working, bathroom radiator luke warm, rest of house cold. We have hot water.

It's worth checking that the pump is working.

Central heating system is 9 years old.

You might have a build up of sludge in the system - see the "How to" page on plumbing for a list of the problems you can experience.

Timer in Kitchen - Danfoss CP15 - if you try and put water and heating on it clicks off.

Don't understand why it should do that. Check everything else first and try again.

Sounds like your system could do with a bit of TLC and a good over haul.

 

[bom1304]

Thank you for your suggestions, we will give them all a try.

What do you mean by insulation has broken down, what do we need to do? Thanks

 

[IanDB]

The immersion heater consists of a heating element in the tank and a thermostat. Eventually - depending on use and water hardness, the element can crack, water gets in and either -BANG - or click depending whether you have a wire fuse or a circuit breaker.

To replace it you need to isolate it from the electricity supply. When you take off the cover of the element you'll find the thermostat. Once disconnected this just pulls out of the casing (it doesn't make contact with the water). Next drain down the hot water tank and unscrew the element assembly - you will need an immersion heater spanner to do this.

Re-fit the new element (using PTFE tape etc), insert the thermostat, wire up, re-fill the system and off you go. Should be as straightforward as that - bet it isn't.

 

[bom1304]

Hmmm, sounds easy (!!) . Will give it a go. Thanks for your instructions, its appreciated.