Hi, I have had a plumber round to quote for fitting a new Vaillant boiler to a small 2 bed, 1 bathroom house.
There is existing iron pipe (I think, definitely not copper as it has threaded fittings) under the floor that feeds a gas fire via a reducer and then normal 15mm copper pipe. I was hoping that the end of the thicker iron pipe could be used to feed the new boiler, but the plumber wants to do a new run from the meter in 28mm pipe that would either go through several rooms in the house, or up the external wall.
As well as being expensive in materials, either option won’t look great. I questioned the need for 28mm and if my existing pipe could be used, but he wanted to be ‘safe and do it properly’. Obviously I want a safe and correct installation, but the use of 28mm seems excessive and he didn’t do any calculations. Is 28mm really necessary, would a calculation with lengths and bends etc show if my existing pipe would be adequate or not?
I have seen a house where the 22mm pipe form the meter goes straight to 15mm under the floor and continues in 15mm all the way to just above the kitchen at the other end of the house, where it turns to 22mm and reappears from the ceiling and feeds a combi boiler and gas hob. This setup always passes the CP12 test every year for correct working pressures, etc – so if that works with 15mm it seems reasonable that the iron or possibly just 22mm could be ok – assuming a calculation was done?
There is existing iron pipe (I think, definitely not copper as it has threaded fittings) under the floor that feeds a gas fire via a reducer and then normal 15mm copper pipe. I was hoping that the end of the thicker iron pipe could be used to feed the new boiler, but the plumber wants to do a new run from the meter in 28mm pipe that would either go through several rooms in the house, or up the external wall.
As well as being expensive in materials, either option won’t look great. I questioned the need for 28mm and if my existing pipe could be used, but he wanted to be ‘safe and do it properly’. Obviously I want a safe and correct installation, but the use of 28mm seems excessive and he didn’t do any calculations. Is 28mm really necessary, would a calculation with lengths and bends etc show if my existing pipe would be adequate or not?
I have seen a house where the 22mm pipe form the meter goes straight to 15mm under the floor and continues in 15mm all the way to just above the kitchen at the other end of the house, where it turns to 22mm and reappears from the ceiling and feeds a combi boiler and gas hob. This setup always passes the CP12 test every year for correct working pressures, etc – so if that works with 15mm it seems reasonable that the iron or possibly just 22mm could be ok – assuming a calculation was done?
