Emptying heating system for the winter - advice

[frediaz]

Now that the temperatures near 0deg are starting, I want to empty the heating system of an unoccupied house, instead of spending money on the heating by leaving the system 'on' under the freeze protection device.

This is a 2 storey house with underfloor heating on the ground floor and radiators on the first floor.

Is it necessary to pump out the water? or can it be just emptied by gravity through the lowest outlet (but it is above the UFH piping). Is it enough to relieve the pressure in the system and even leave it open so that pressure does not build up if the remaining water freezes?

Thanks

 

[JohnD]

you will never get all of it out.

have you considered adding fernox Antifreze?

this could save you a lot of work, and the cost of fresh inhibitor.

 

[frediaz]

you will never get all of it out.

have you considered adding fernox Antifreze?

this could save you a lot of work, and the cost of fresh inhibitor.

When the plumber commissioned the system, he ticked the box "inhibitor added". Is the inhibitor both against corrosion and freezing? Will it be better to add more antifreeze anyway?

If I empty the system, will I need to get it re-commissioned when it is used again, with the pain to get all the air out and the cost?

 

[JohnD]

inhibitor is anti-corrosion, but the big makers also make a compatible antifreeze that you can put in as well.

a typical house will have less than 100 litres of water in the system which will help you calculate how much you need.

you will certainly have to get all the air out when you refill if you have drained

generally you can't get it water of the boiler (without enormous difficulty) which will make you sad if you have to buy a new one due to freezing.

 

[frediaz]

Thanks for the feed-back. The boiler manufacturer says it is OK to use antifreeze with his boiler.