Boiler working too hard equal high bills

[Agile]

Please realise that the previous post is stating totally incorrect facts!

The high pipe loss will make no difference to the efficiency or operation of your boiler.

Its such a pity that this forum does not allow gas registered engineers to show that when they post here!

Tony

 

[mickyg]

this is the problem with this forum now, too many arm chair experts with not a hint of experience or fact to back up stupid comments. Op will be royally confused now

 

[DP]

Tipper wrote

The size of the gas pipework is not the issue unless it were so small that it restricted the gas consumption...which it obviously isn't!

The pressure drop on the gas line will have a detrimental effect as FGA reading may be out of kilter due to insufficient gas pressure at the gas valve. Other appliances may well be hooked onto the gas line so things could be worst if say a gas hob is running and a fire too when boiler is required to heat water (maximum demand). The boiler may well be ticking over during heating mode but it needs plenty gas when HW is run

Tony wrote

The high pipe loss will make no difference to the efficiency or operation of your boiler.

I can produce facts and figures to say otherwise


OP, why do you not call the fitter back and let him provide correctly sized gas line?

 

[jklondon]

[/quote]

I can produce facts and figures to say otherwise


OP, why do you not call the fitter back and let him provide correctly sized gas line?

[/quote]

Its an inherited problem when we brought the house, dont know who fitter is.

So really confused as to whether this is causing extra ££ or not. Looking to get someone out to help.

 

[Agile]

Based on the apparent facts we have been given I would not agree.

With a nominal meter pressure of 21 mbar and a pipe loss of 4 mbar that will give 17 mbar working pressure at the boiler in this case.

We must assume the engineer correctly tested those pressures with other appliances on if relevant. It will have been more than 15 mbar otherwise he would have tried to turn it off.

Virtually all premix boilers will work down to less than 15 mbar without any significant change to the operating parameters because the zero pressure gas valve is not needing to give a positive burner pressure.

Tony.

 

[jklondon]

Apologies in advance for crossing issues but it is probably related to my high ££. I realised last night that the boiler keeps on going on during the night and staying on for most of it. It was not heating thermostat driven so assuming water - but this doesnt seem normal right?

 

[Agile]

You may have a cylinder stat set too high, it should only be about 55 C.

The boler flow also has to be at least 10 C higher than the cylinder.

Regardless you should have a programmer so that you can only let it heat water dduring certain hours!

Tony

 

[mickyg]

just so you know, I can tell you for a FACT that a 5mbar pressure drop won't affect the way your boiler works or its efficiency. However Im not willing to disclose gas safety information on the open forum, only to RGIs in the CC.

 

[Agile]

I am glad that you agree with me, Micky!

That leaves DP to present his "evidence" to the contrary in the CC !

 

[DP]

Tony following was cut and pasted from the MIs

Caution! Natural gas:
DO NOT proceed with adjustment or attempt to
put the unit into service if the inlet working
pressure lies outside the 17–25 mbar range.

If the pressure at the meter was 21mb (rarely is) then at the appliance it will be 16mb if the figure furnished by OP is to be believed (5bar). It is unknown what the actual working pressure at the meter is. It may well be on the low side at 19mb out to give pressure at the appliance of 14mb (well outside the figure the MI stipulates). Do you know for a FACT if it is indeed 5mbar with boiler in test mode? Will it remain the same if other appliance, if any fired up?

Tony wrote
Quote:
The high pipe loss will make no difference to the efficiency or operation of your boiler.

Talking of high loss. My evidence relates to fitting a boiler with 28mm gas line meter to boiler 16mb at the meter. At finish of instal FGA reading were in the gutter. Transco came out and did their work and FGA reading were as per spec. Now can you tell me if the efficiency was compromised. Ecotec MI states no adjustmnent should be carried out if the working pressure is incorrect.

Micky, I take it you would be happy to walk away from a job with substandard gas line as this poster has when the MI clearly states what the gas pressure operation window is, bearing in mind the loss figure presented may not be the true reading? I regularly come across instals where a boiler has been chaged but gas line remains the same, so a new combi hooked onto a 15mm gas line shared by a hob, even a free standing oven, now has a flame reduction at the hob when 'she' runs a hot tap.

Another question that comes to mind, was a FGA test carried out? if yes what were the figures on it. Perhaps the OP could provide these as surely the last engineer must have carried out a FGA.

 

[mickyg]

Micky, I take it you would be happy to walk away from a job with substandard gas line as this poster has when the MI clearly states what the gas pressure operation window is, bearing in mind the loss figure presented may not be the true reading? I regularly come across instals where a boiler has been chaged but gas line remains the same, so a new combi hooked onto a 15mm gas line shared by a hob, even a free standing oven, now has a flame reduction at the hob when 'she' runs a hot tap.

Another question that comes to mind, was a FGA test carried out? if yes what were the figures on it. Perhaps the OP could provide these as surely the last engineer must have carried out a FGA.

stop talking out of your ar5e. I stated a fact which I can back up but not here. Where did i say it was ok to have such a pressure drop? where did i say i would walk away happy.
I was merely pointing out that an undersized supply causing a 5mbar drop across the carcass will not effect efficiency which is a fact. I didn't state anything else so don't presume anything.

 

[jklondon]

Appreciate the responses even though I am a tad confused still - spoke to my energy supplier they said if your losing pressure ~4bars must be a leak! Even though I cant smell anything and had other people in the house to verify that ...

 

[big-all]

Appreciate the responses even though I am a tad confused still - spoke to my energy supplier they said if your losing pressure ~4bars must be a leak! Even though I cant smell anything and had other people in the house to verify that ...

what option did you choose ??
it probably was just a call center person guessing as they are not technical people

 

[Dan Robinson]

I think the phrase "too much information is a bad thing" is rather pertinent here

 

[swbjackson]

Appreciate the responses even though I am a tad confused still - spoke to my energy supplier they said if your losing pressure ~4bars must be a leak! Even though I cant smell anything and had other people in the house to verify that ...

You, and your supplier, are getting two different things mixed up. When an engineer talks about pressure drop across a pipe run he is talking about the frictional losses that occur when gas passes through the pipe. The regulations state that this should be a maximum of 1 mbar between the meter and the appliance inlet. There will often be an additional pressure loss between the appliance inlet and the test point on the appliance and the manufacturer will normally state this amount in the instructions. If the pressure loss exceeds this amount the extra gas is not leaking, not enough gas can get though the pipe so the pressure is lower.