Combi Boilers

[kenny1234]

I have a Gloworm flexicom 30cx.
Question one--Am i correct in thinking that steam; not water is pumped around the radiators?
Question two--Watching the steam coming out of the roof vent this morning made me think that a lot of water must be being used for this to happen : yet they say that the system is sealed and the only time i need to add to it is when the pressure gets low.??

[bhg481]

When you burn oil or gas, water is one of the combustion products. The steam you see coming from your boiler flue is the exhaust from the boiler and is completely separate from the water being heated.

[melv16]

It's water that's in your radiators. The 'steam' that you can see is the exhaust gases from the gas that is used to heat up the water.

[Old_Geezer]

You spend a lot of time bleeding the radiators if all that was pumped around was steam.

[kenny1234]

Many thanks all.--I must have mis-read somewhere the bit about steam being in the radiators!!!

[New Judge]

Also, of course kenny, even if it waas steam, as soon as it cooled it would condense into water.