Can't believe it - we now can't reach our heating engineer! Bet he's on holiday... unlucky timing 
Going to give him until the end of today - then try others.
Also going to chase up Remeha.
Will keep everyone posted for reference (especially with regard to cost and timings - and warranty issue).
Going to give him until the end of today - then try others.
Also going to chase up Remeha.
Will keep everyone posted for reference (especially with regard to cost and timings - and warranty issue).