Discuss Pressure drop across gas pipe in the Plumbing Jobs | The Job-board area at PlumbersForums.net

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Rtm

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Currently having an issue I can't figure out and could do with maybe some pointers from some of the more experienced members on here. Standing pressure at meter is 22.9 mbar and working pressure in 21.8mbar at inlet to boiler working pressure drops to 10mbar. It's a short pipe run so undersized pipework is definitely not the cause. All visible pipework appears undamaged as well. What could cause such a large pressure drop across say 5m of gas pipe? Property has been vacant for a few months and unused if that makes any difference. Any suggestions would be appreciated
 
Get the networks out to check the regulator
 
Get the networks out to check the regulator
Or a collapsed main. Had one earlier in the year when the old main had collapsed. Vaillant Ecotec plus I had fittedthe year before running on 8mb full load
 
It's an old baxi bermuda bbu. Taking inlet pressure off the inlet at gas valve and also off the gas fire in front of it. Yes I'm gas safe, newly qualified.
 
Working pressure is fine at the meter though just by the time it gets to an old bbu it's dropped to 10mbar at the inlet to the gas valve

You have to understand the difference and interaction between flow and pressure. If you have enough standing pressure, but it drops too much when wotking, you do not have enough flow. You have been given the probable answers above, faulty regulator or problem with the main. Think of it as, when the boiler fires, it uses gas, which must be replaced by the same amount of gas flowing in from the main to replace it, or there will be less gas in the pipe. Less gas = less pressure. Slow flowing gas will still build up pressure when it is not being used.
 
I had the same issue once on an install of a replacement boiler. Contacted the gas supplier who changed the regulator and problem solved.
 
If you got 21mb working pressure at meter but 10mb at appliance ...how is that a faulty regulator?
 
hello all , i am also a newby but have 40 years in refrigeration and a/c . would it be safe to say , have you checked the pressure at the meter when app is running as well , and if it is acceptable then it is either the regulator , pipe damage/blockage ?
 
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hello all , i am also a newby but have 40 years in refrigeration and a/c . would it be safe to say , have you checked the pressure at the meter when app is running as well , and if it is acceptable then it is either the regulator , pipe damage/blockage ?

Gofo, if he has 21mb working pressure at meter it cant be the regulator...the regulator is upstream of the meter test nipple.

Assuming hes not taking a burner pressure reading its either a blockage or GV to blame
 
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