Draining down a HW system with back boiler

[Tim Downie]

I need to drain a water system down in an empty house that has an old back boiler that was still in use until recently.

Would I be right in thinking that a back boiler *must* have a drain c*ck somewhere in the system at the lowest point or were they sometimes installed without one?

Tim

[Owain]

Mine was installed without one :-(

Owain

[hugh]

Very dangerous, I would have thought. Last winter we had a massive house explosion near us with one fatality. Elderly gentleman on his own died. Then came the very cold weather. Elderly sister accompanied by her daughter came to sort out his bungalow. Put on central heating followed by huge bang as frozen boiler exploded. Blew the roof off and virtually demolished the bungalow.

[Tim Downie]

Unlikely in this particular case as there is no CH boiler, only a gas = fire in an old open fireplace. I don't know whether the chimney is even = lined. All I do know is that if the gas fire is left on for a long time = the HW tank bcomes vaguely tepid which suggests to me that there is a = still functioning back-boiler built into the fireplace.

I doubt that the gas fire is capable of putting enough heat into the = back boiler for any siginifant pressurisation to occur.

Tim

[hugh]

In message , Tim Downie writes

I had assumed you were talking about an integral fire/back boiler such as a Baxi. Presumably it had had a solid fuel system in place. There would still be a need for a drain c*ck with the old system for the same reason.