Unvented Undersink Water Heaters. For D.I.Yers.

I would say that generally the taps (or radiators) would go on last

Only for new installations/additions - for alterations they're likely to be there already.

My gotcha with soldered fittings was water dripping into the joint from a gate valve that didn't quite seal properly when fully off. I gather the old plumbers trick is to shove some white bread into the pipe before assembling/soldering - it blocks/absorbs any small trickle of water while the joint is made, but is readily broken down and forced out of taps when the main supply is back on. Probably not a good idea with some modern fittings with a filter on the inlet though…

    - Andy.

I would say that generally the taps (or radiators) would go on last

Only for new installations/additions - for alterations they're likely to be there already.

My gotcha with soldered fittings was water dripping into the joint from a gate valve that didn't quite seal properly when fully off. I gather the old plumbers trick is to shove some white bread into the pipe before assembling/soldering - it blocks/absorbs any small trickle of water while the joint is made, but is readily broken down and forced out of taps when the main supply is back on. Probably not a good idea with some modern fittings with a filter on the inlet though…

    - Andy.