New gas main, low pressure.

[hydrotherm]

Had a service to do last week on a Remeha Avanta. Put it on full rate to do FGA and it kept locking out. Checked pressure at meter and got 25 mbar standing 16 working. Minimum required at appliance according to MIs was 17mbar. There was a new regulator and ECV fitted and signs of a new service . Rang ESP who attended and confirmed that when they put the new plastic service pipe through the old iron pipe it had kinked on one of the bends, solution was to dig up old and lay new. Think we are going to get a lot of this in the future with pressure being critical on the modern boiler. Left the customer waiting for the dig team and looking at his lovely recently laid driveway.

 

[mountainman]

Well diagnosed though :smile5:

 

[ecowarm]

The whole drive wont be ruined, just the odd hole here and there as they will "mole" the new supply

 

[Pssst]

Old SPs are sometimes renewed using insertable corrugated plastic pipe. Its diameter isnt that much anyway,usually about 20mm internal diameter and it can kink. Additionally,the corrugated profile can cause more pressure drop than one would get with smooth bore PE pipe. It is not unknown for this and/or smooth bore 20mm pe pipe to be run in excessive lengths. A simple formula can be used to calculate the expected pressure at the delivery end of a pipe for a given inlet pressure/flow rate/diameter etc but thats really down to the network provider !

My MO for dealing with this is to fit guage on ecv,fit guage on meter outlet,and see how it looks.

 

[midge]

That corrugated stuff is called Serviflex and is made to insert old 3/4" iron.

Whether it provides enough capacity depends on length and pressure, one problem is that the mains pressure, while in theory can be up to 75mbar, can be reduced especially in summer, to assist with leak rates.

What always worries me is that the Gas Safe installer can get a correct pressure while he is working, but a week later its low. Just something to bear in mind.