Help Help and information on all topics relating to your central heating, air conditioning and ventilation issues.

[paul77]

where after replacing a 15yr old verkona boiler and have had 3 quotes so far 1 was for a baxi boiler which doesnt seem to have good feedback so i dont think we will be going with that.

a vaillant which seems to get good reviews

Now BG have been out with there quote,which apparently! means alot of work which is there reason for a big quote anyway what i need help with...we have a 15mm gas inlet pipe into our boiler at the moment non of the ppl we have had out have mentioned that the gas inlet pipe has to be bigger??? although the specs from the boilers we have looked at say 15mm the guy from BG insists that the other dealers would fit it in with a 15mm pipe but would be wrong by a million mile's and the pipe needs to be bigger as 15mm pipe would make any guarantee null and void???

Is this right?

[htg engineer]

yes, has to be at least 22mm gas supply to boiler. I say at least as for larger houses sometimes 1" gas pipes are taken from the meter then reduced to 22mm.

[paul77]

So what about just replacing the boiler and using the existing 15mm pipe?

As the brochure for the vaillant spec say's 15mm??

There is a big difference not only in price but the amount of work BG are wanting to do as oppose to the 2/3 other quotes we have had

Tbh the price BG have quoted us would be a lot to pull out and would mean ripping up all the upstairs floor boards.

If we could go with one of the other quote's id rather do that....would it make much difference?

[htg engineer]

22mm gas supply needed for combi boilers.

Don't let BG do the work, they're a rip off. They're not interested in repairing or customer satisfaction - all they want is to sell and install boilers. At ridiculous prices.

If someone has given you a good price - let them do it, they've probably included the price for the gas pipe anyway.

Have they actually said they will fit the boiler to a 15mm supply ?

Make sure you insist on a 22mm gas supply for the boiler.

[paul77]

No the guy where going with didnt mention about 22mm though the boiler we are looking at is 15mm gas inlet.

But if he suggests the work BG have then i will be going with the 15mm :(

We only have a small house if that makes any difference

[htg engineer]

The gas supply HAS to be 22mm. The size of the gas connection to the boiler is irrelevent.

Not Vaillant or any other boiler manufacturer would state the size of the gas pipe required - because they can't. You need to know the length of the gas run, the amount of fittings used, other appliances that are connected to the carcass, the gas rate of the boiler.

the boiler has a 15mm connection - then it has to be 22mm to within 1 metre of boiler.

If you connect a combi boiler to a 15mm gas supply, the boiler will not operate as efficiently as it should.

The combustion will not be correct.

If you have a gas fire or cooker on and you open the hot tap the cooker or fire will probably go out - causing a dangerous situation.

If the boiler is not installed correctly or the incorrect gas rate is set, then your boiler warranty may also be void.

[paul77]

Had our last quote today and mentioned our need for the 22mm pipe :) the guy verified this thanks for the help htg

One last question if u dont mind :) we have been offered a worcester green star 28i junior

So it would be either that or the vaillant boiler the worcester is more expensive but the guy included the sorting out our pipe where as the vaillant guy never made mention of it.


Any feedback on iguana and the worcester greenstar 28i junior?