Pipe to boiler is "under sized" after 2 years?

Ray Palmer

We got a new boiler installed about 2 years ago and had it serviced a few month ago by an Eir contractor. He mentioned that the pipe was under sized at the time. About 2 weeks ago the boiler started making a very loud rumbling noise. Call the Eir guy out and he says it is because the pipe is "under sized" as I try to get him to explain how is it possible that the boiler before and then this boiler were working fine and then suddenly the pipe i under sized. He then does another test and says the gas pressure coming in is too low. I call board gas networks and the guy comes out and say the pressure is a little low and the Eir guy is talking nonsense. The Eir guy was meant to call back down but never did. The boiler worked fine for about 30 minutes and then acted the same way. He will probably be down today saying the pipe is undersized again.

Can a pipe become suddenly under sized after working fine? Is the original installer at fault in anyway?

I found the Eir guy very difficult to deal with as he was saying too small and undersized randomly and was very inconsistent in what he was saying, He was pointing to the manual saying it said pressure had to to e 21.5 at the boiler when it actually showed 17.5-21.5. He said the boiler was over 10 years old while holding the cert showing when it was installed and it was new. I don't think he is trying to scam me just not the brightest bulb. When he serviced the heating he had to come back because he left the gas switched off and the boiler in some service mode, Hard to trust somebody like this

A gas pipe feeding a appliance is either sized correctly or it is not, any appliance being fitted would need the pipe work checked to prove it is suitable and if not the pipe size would need to be increased.

There are times where other issues could mimic a pipe sizing problem but usually I find low working gas pressure is due to incorrectly sized pipe.

i haven’t worked on your boiler but I would be surprised if it is a low gas pressure issue causing your problem as I would expect it to have been a problem from the start but if you do have low pressure it can give a RGI a get out of jail free card until the gas pipe is sized correctly.

K.Flyer

What is the make and model of the boiler?

Did the rumbling sounds occur before the service or after it had been serviced and up to now have there been any issues with the boiler?

Ray Palmer

https://www.boards.ie/discussion/comment/117684194#Comment_117684194

His claim was that the pipe itself was not too small and "undersized" does not mean too small just that the pressure coming to the boiler means the various bends in the pipe could mean the pressure was too low meaning it was "undersized". He was interchanging "undersized" and "too small" but clarified he meant not enough pressure claiming carbon can build up causing reduced pressure. Didn't sound right to me. It was not an issue until a month after he serviced the boiler.

Anyway he came back down and checked the pressure and now says the air intake is missing a seal and the issue is not enough air intake and he had to order the seal. There is a possibility the neighbour pulled out the pipe and shoved it back in where they did some ivy removal but I am not sure they did or that the seal would disappear as a result as opposed to be damaged. So over all the heating engineer has claimed 3 different issues 1, the incoming supply was under pressure(regulator replaced),2, the pipe in the house was "undersized" (pressure reading within the limits of the manual),3, the air intake is missing a seal that the original installer missed.