Changing radiator valve

shown73

All the diy forums state that it is necessary to drain the system in order to do this, but I have been told that there is a better way. Simply block the outlet and overflow(?), from the header tank, thus creating a vacuum, and change valve without significant leaks all over the carpet. Has anyone tried this? It would be lovely if it works. Any ideas on what to use to block pipes? Corks? Very handy tip, if it works...

ariba10

I would rather you try that than myself!

The_Pedant

I would be very surprised if that would be sufficient. There's a whole bunch of reasons why you could have a not so insignificant amount of the water in the system still run out.

Yes, in some *very* limited scenarios it may work in but it's not something I'd want to put any trust in. If it were that easy, I would expect the plumbers to use such a trick!

For starters, especially if it's a downstairs radiator, just think of the weight of water in the system above it, bearing in mind that this is slightly under pressure. 20 minutes of time to drain & refill sounds like a much better solution than risking it.

K.

EliteHeat

You have to block the open vent and the cold feed into the system. Any automatic vents must also be shut.

Once this has been done breaking into any single pipe will result in a small amount of leakage until the lock holds. If, at this point you break into another pipe you will have a flood on your hands!

Plumbers 'bung' systems like this all the time simply to save time. DIY people rarely have to worry about saving a few minutes here or there and usually place greater value on their carpets