Some gas distributors are not always carrying out adequate gas supply checks to properties impacted by pipeline changes, Worcester Bosch has warned.
Martyn Bridges, director of technical communication and product management, says that the boiler gas supply checks carried out by distributors are not always sufficient to ensure the correct pressure and volume is still available.
The average household should expect an incoming supply of around six cubic metres of gas per-hour.
But with polythene pipes quite regularly being routed through existing steel pipework to upgrade the gas distribution network, flow diameters are being reduced. The result can often be below-average gas supplies reaching affected properties.
Martyn said: “For some properties, as little as 4-5 cubic metres of gas is entering a property. For those households with a 40-kilowatt combi, 3.7 cubic metres are required to power the boiler alone when on full output. Throw into the mix a gas fire and cooker being in use, and the insufficient volumes entering the property will become noticeably evident.”
The issue is becoming a problem with homeowners, installers and boiler manufacturers as they are forced to pay for call-outs, often some time after the initial boiler installation, only to discover that the issue is the gas pressure entering the house and not the boiler or the installation.
Martyn continued: “The distributors could be doing more to check the affected household’s gas supply. They could begin by putting the boiler into full service mode, as doing this ensures that it is firing at full rate. Only then will the gas pressure indicate that the volume of gas entering the property is insufficient.
“The last resort is a little more rudimentary but would work well for those engineers without the knowledge needed to put a particular combi-boiler into full service mode.
“Those distributors who do not know how to turn the boiler on to full service mode, should take the simple step of turning the hot water thermostat up to its highest setting and then open up two to three hot water taps. If there is a gas cooker or fire, turn those on as well, the incoming gas pressure at the meter test point can then be checked,” he said.
“Whether they opt for the rudimentary step or the more thorough and reliable full-service mode route, distributors need to be checking household supplies before they leave the job.”