Pipes in concrete floor with combi boiler

[computermike]

I am looking to replace an oldish boiler and hot tank with a combi boiler. The house dates from around 1968 and quite possibly the (copper) piping could be that old. I had someone round to give a quote and they said they would not recommend a combi boiler because the piping downstairs was buried in concrete floors and the extra pressure from a combi might increase the possibility of a leak. Other people round to quote have not mentioned it. Our neighbour with an almost identical house has just had this done and so far has had no problems. Is this something I should worry about enough to change my plans? I am really keen to get water tank(s) out of the loft.
Thanks

 

[SimonG]

I have a disclaimer on my estimates that states no gaurantee for any existing pipes and fittings, but I also discuss the issue with the customer.

You could try a pressure test prior to going ahead with any works. You would ideally need to test to 4.5 bar, pressure relief on a combi will operate at 3.0 bar so effectively 1.5 x max pressure. But again if something goes pop then it's an issue.

You could get the combi and operate the heating side as open vented via a plate heat exchanger, but sounds like you want rid of the tanks, so maybe not an option.

 

[king of pipes]

Intergas have combi boilers that can operate at lower pressures just unplug the flow sensor fit a pressure reducing valve and the system can operate at 0.75 - 1bar . Kop

 

[Timmy D]

Be aware that you’ll likely require a gas pipe upgrade.

And check your mains pressure/flow rate as a combi may not be suitable.