Close off all radiators

6 Jan 2020
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United Kingdom
I had a quick look at the FAQ but could not see anything related to this.

I have not used the central heating in my house for about three years. The immersion heater provides hot water and that is it. The boiler is switched off, the pump that services the radiators is switched off and the 'central heating switch' is switched off.

Yesterday, one of the radiators sprang a leak - looks like the seal went around one of the front corners (it has a flat face - not a 'column' radiator). Luckily, I caught it before it had time to do any serious damage. I have now closed off both the valves and the radiator is drained.

I would like to know if it OK to do the same with the remaining radiators. The system is 26 years old in a two-bedroom house. There are 5 radiators in total. Is it safe to do this? I don't want any of the remaining radiators to spring a leak due to old age, and isolating each of them seems to be the best bet - if any do leak, then only one radiator's worth of water will be spilt.

Thank you.
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Better to drain it all down, then there is nothing to leak. Turn the boiler off electrically and turn off the gas to it. (Likely to have a suitable valve under the boiler).
However, if you aren't going to use the boiler, it will probably fail and become unusable (seals drying out, corrosion etc.). This is likely to be an issue if you want to sell the property. Similar issues with radiators. Even if empty there will probably be sufficient moisture / water within them to cause them to rust, and if anyone does want to use the central heating, it may all need to be replaced.
Thanks a lot for replying. The reason the system is not used is that there is sludge in the system and I have been quoted £5k to replace pipes/boiler/rads (the pipes are narrow bore and likely furred up and the boiler started 'kettling' which is why it is no longer used). I don't have £5k so decided to turn it all off and use plug-in oil-filled radiators instead which work a treat.

I will see about getting someone in to drain the system.

Hello again.

Unfortunately, I can't get anyone in before I have to go away. I've turned the valves off on the radiator but there is still a very slow drip - once every 2 or 3 seconds. Can anyone help me with how to turn off the water flow to the heating system, please?

Below are 6 photos showing the immersion heater and the pumps, and the boiler. The third image shows the two pumps each of which has a valve above and below (labelled 1 - 4). The green pump on the left was installed about four years ago because its predecessor had stopped working (it was sludged up).

The last three photos show the area above the boiler where two pipes go in/come out and the bottom of the boiler where just a single pipe goes in, and a close up of the inside area where the bottom pipe comes through.

Is it simply a case of tightening up one or more of the valves on the pumps? Or do I need to do anything with the boiler?

Sorry for the questions. I'm really paranoid about it now.






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1. The only guaranteed way to stop the leak is to drain the system. You could do this as follows:
1a. Turn the boiler off.
1b. Turn the water supply to the feed and expansion tank (F&E) in the loft off, or at least tie up the ballcock and make sure no water can enter.
1c. Ideally, empty and clean the F&E tank so you don't wash any muck from it through the system. If your system is already blocked, may not be worth it.
1d. I don't think you will have any with a two pump system, but if you do, set both motorised valves manually open. Slide lever arm and latch in open position.
1e. Find a drain point. Likely to be on a downstairs radiator, or even outside. Look up drain off cock to see what it looks like, although sometimes they are incorporated into radiator valves. Attach a hose, run to outside, and open drain off cock. Should drain OK.
1f. If no drain off cock, or doesn't work, pick a downstairs radiator. Close both valves (count number of 1/8 turns of lock shield side, and when refilling, re-open same number of 1/8 turns). Undo attachment point of one valve to radiator (NOT to pipework), place tray under to catch water in radiator, have plenty of old towels handy. Above all keep water of carpets / anything which stains. When water out of radiator, tape hosepipe to now open end of valve. Make sure its firmly attached. Run hose to outside, open both valves and system will drain.
2. As an alternative, and given that you do not and will not use the system fit a self piercing tap to any convenient piece of (ground floor, as low as possible) pipework, and use that to drain down. E.g. Screwfix 9543R.
Thanks again for taking the time to help. I'm afraid that is all double-dutch to me and way beyond my paltry DIY skills. I will just turn the water off at the stopcock while I'm away and then get a plumber in to sort it out for me after I return.

Cheers! Once again, thank you :)

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