How long can I leave a CH system empty of water?

[Tubbsup]

That's a good idea Harry. Thank you. I have some very valid help now.

 

[BlueLoo]

To be a bit technical,

Any corrosion will form because you have a mixture of air and water. Remember that experiment you did in school with a nail, a test tube and some cotton wool? This is the same thing.

So you either have to have the system fully drained and dried and seal, or, fully filled, to stop air/water mixing on the internal rad surfaces.
As for the pipes, well, modern houses are mostly PEX/Poly and if so, i can't see this being an issue. Stagnation will be though.

My advice (i am not a plumber) is to spend £15 on some inhibitor and drain the system you have as best you can, then fill it up inc, inhibitor and try to remove as much air out of it as you can and this should be fine until you get a new boiler.

Whilst you have the system down, fit some trv's in the conservatory and put them on frost setting. This will protect your conservatory and the piping.

 

[Harry Bloomfield]

Whilst you have the system down, fit some trv's in the conservatory and put them on frost setting. This will protect your conservatory and the piping.

But not if his boiler is out of commission, nor even if his boiler is working, but only that area gets below 5C. The only way the later will work, is to install a frost stat in the conservatory - which was why insulating the pipes was suggested.

 

[BlueLoo]

But not if his boiler is out of commission, nor even if his boiler is working, but only that area gets below 5C. The only way the later will work, is to install a frost stat in the conservatory - which was why insulating the pipes was suggested.

The "No boiler=No heat" is obvious.

Why a frost stat? A TRV has a frost setting on it. Just use that.
Obviously, one is assuming the conservatory rad is a working circuit. No, if the rad valves are turned off, this wont work either but then again, with a TRV set to frost, why on earth would you turn it off?

 

[Harry Bloomfield]

The "No boiler=No heat" is obvious.

Why a frost stat? A TRV has a frost setting on it. Just use that.
Obviously, one is assuming the conservatory rad is a working circuit. No, if the rad valves are turned off, this wont work either but then again, with a TRV set to frost, why on earth would you turn it off?

Do you not know how a heating system works?

How is the frost setting on a TRV, going to signal the boiler that it needs to fire?

Why a frost stat? Because the boiler, assuming it was in working order, would need to be triggered to fire. How else are you going to get heat into the system?

The op's concern and question was protecting his system from damage, in the event his boiler were to become faulty. Obviously he has serious concerns that his boiler is unreliable.

 

[BlueLoo]

Do you not know how a heating system works?

How is the frost setting on a TRV, going to signal the boiler that it needs to fire?

Why a frost stat? Because the boiler, assuming it was in working order, would need to be triggered to fire. How else are you going to get heat into the system?

The op's concern and question was protecting his system from damage, in the event his boiler were to become faulty. Obviously he has serious concerns that his boiler is unreliable.

I do know how a heating system works. (mostly).

I think the normal heating firing up would cycle through the room enough to protect from frost. This isn't some shed at the back of the house.
I mean, sure, if the zone isn't firing up enough to do that then a frost stat may be an idea.
A TRV on the rad wouldn't do any harm regardless.

Or, if the room really is just a summer room, bin off the rad altogether and fit some IR heaters in the ceiling. Much better usability and probably cheaper to run if its a once-in-a-blue-moon thing. Any no more worries about the pipe freezing!