central heating problem-all radiators cold?

Question

I have an open type gas central heating system. With the heating on, the pipe before and after the pump are hot there is a 90 degree bend( with a bleed valve) after which the pipe is cold. This is the first time the heating has been "on" since last winter, the hot water is and has been fine. I have bleed all radiators no differeance, I drained the system then refilled and re bled still no differance. This happened (or something similar) a couple of years ago and the guys said an air lock and put in the bled valve at the 90 degree bend. Any ideas? Thanks

Answer 1

As the pipework is hot both sides of pump - is is clear that your boiler is firing up and heating the water (this means your thermostat and boiler are ok).

The bleed valve to look at is the 1 at the 90 degree bend - after which the pipework is cold - - if the pipework at this point has air in it - the water will not pass it, and it will be cold.

Alternatively, the previous advice to check your pump is valid - - as your boiler is heating the water, the pipework will get hot, because the water inside it is hot, but only in pipework upwards of the boiler.

If your pump is not running the water will not circulate, nor will any pipework get hot if your bend has an air lock.

it is possible the pump has seized, particularly likely if it has been running with air, rather than water in system (it's overheated).

Try switching boiler off, letting pump cool - then re-start pump - a light tap on pump sometimes helps to free it at this point.

Answer 2

Central Heating Problems Cold Radiators

Answer 3

Central Heating Radiators Problems

Answer 4

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RE:
central heating problem-all radiators cold?
I have an open type gas central heating system. With the heating on, the pipe before and after the pump are hot there is a 90 degree bend( with a bleed valve) after which the pipe is cold. This is the first time the heating has been "on" since last winter, the hot water is and has been...

Answer 5

check that the circulating pump is working by putting the metal end of the screwdriver against the pump and put your ear to the handle. make sure that the pump is turned on. Another fault could be that the room thermostat is turned down (if you have one). Finally, if all this is in order, then you will have to open a drain off in the system and pull water through until it is hot. thats all I can suggest. Hope it helps.

Answer 6

Probable cause--
One of the products of radiator water is iron oxide deposits and one day its build up settles in the pump and this causes the impeller to stick.
Solution-
Select the top speed on the pump's casing and if this doesn't clear it remove the pump and do so.
Test the pump before returning to check its working.
Replace pump if necessary.
Tools-
Pump pliers £4 each and you will need two.

Don't forget to close the valve each side of the pump

Answer 7

Is your pump working? If so try opening the 90 degree bleed valve.

Answer 8

There is a brass nut on the end of the pump, unscrew using a penny ( It has a big slot) insert an electrical screwdriver an give it a flick either way it will clear, if it starts you will hear at hitting the end of the screwdriver.. Replace brass nut, Dont worry about the small amount of water that will come out, its normal.

Answer 9

YOU NEED TO TURN THE PUMP OFF AND OPEN THE BLEED VALVE FULLY WATER SHOULD POUR OUT THEN BLEED THE LAST RAD IN THE LINE , CLOE THE BLED VALVE THEN THE RAD AS THE WATER AND AIR LOCK COME THROUGH.
YOU HAVE TO ENSURE A GOOD FLOW OF WATER FROM THE LAST RAD

Answer 10

may sound stupid but is the pump working , is there power to it . my advice get a corgi registered pro in to check your system