Going away and central heating

[hansi]

I'm going away in a couple of weeks to OZ/New Zealand and it's the first time I've been away in the winter. When I go away in the summer, I turn of the gas and water supply to be on the safe side, as I once had a horrendous experience when the ball cock in the header tank snapped, and water came rushing out of the overflow. I would like to think that we won't get a "big freeze" situation and I had a look in the loft, it's quite well insulated and all the pipes to the tank are wrapped in insulating sleeves. I would rather not leave the central heating system on because of my past problems and I live in a link house and a certain amount of heat is generated from the adjoining properties. Would I be fairly safe in switching everythig off at this time of the year? You don't hear of pipes bursting like the old days, do you?

 

[ArtfulBodger]

If you really want to be safe and don't want to be worrying when you're away, why not drain down all systems? if you haven't got any water you can't have a leak can you?

 

[hansi]

Thanks, how exactly do I do that, and what do I have to do when I return please?

is it just a matter of closing the stop cock under the sink and letting the hot water tank empty?

 

[ArtfulBodger]

is it just a matter of closing the stop cock under the sink and letting the hot water tank empty?

No, you need to drain the cold water system, the central heating system and the hot water cylinder.

Start off by turning off the stop cock, the boiler and the immersion heater, if you have one.

Next find the drain off on for the heating system and attach a hose to it. Open the little square nut and drain completely, remember to open the bleed valves in the rads to ensure that all the water empties.

Open a cold tap to drain the cold water cistern.

Find the drain off for the HWC, this should be on the cold feed to the cylinder. Attach a hose, open the nut and empty.

You may want to tie up both valves in the loft for the cold water cistern and the header tank.

That's your system drained, but don't expect the drain offs to work - they often stick. Filling up is pretty much the reverse of emptying, but with the possibility of airlocks just to keep you on your toes

 

[croydoncorgi]

Hang on a tick....
How long are you going away for?
Draining everything means :
- you'll have to fill it all up again when you get back
- you'll lose all the corrosion inhibitor in the CH system, which will have to be replenished.

If you turn off the main water stop cock, open hot AND cold taps in the kitchen, let the water run out and leave the stopcock shut and the sink taps open, you will have drained the cold water storage tank and all the pipes. The HW cylinder will still be full but IF your house is 'linked' it's quite unlikely that the cylinder will freeze EXCEPT in a very severe cold snap. Similarly with the CH system, with the water supply turned off, even if everything froze up and then melted, there would NOT be a major flood. At worst (depending where the pipe burst occurred), the contents of the rads and the pipework would leak out but at most would be about 50 litres for an average house.

Then, when you return, check carefully that nothing has frozen up and then melted BEFORE you turn the water back on!

If you're going away for months, drain off completely. For weeks, do a less drastic alternative.

 

[hansi]

Thanks, croydoncorgi, Im going away for about three weeks, so I think your alternative is better, but I thought that if I turned the stop cock off and ran off the cold water first and then the hot water, then the HW cylinder in the airing cupboard would empty. Apparently, not so. But I will use your suggestions. At least the header tanks won't have any water in it to freeze!

 

[croydoncorgi]

Hot water cylinder fills at the bottom but empties from the top, so it will still be full even when the HW taps stop running.