Low/ No Gas pressure...please help

[Resolute]

Having read the further info you've now posted I would suggest taking a working pressure on the original boiler, if this is fine then you can rule out anything wrong with the existing meter and regulator. Then turn off all appliances except the new boiler and see if it fires. If standing pressure is 21mb but drops to zero when it fires it would suggest to me that there is a blockage/restriction in the new pipe run.

 

[Bernie2]

It does seem a bit of an unusual problem. Basically you are looking at two problems I suppose, if you are getting 21mb at the boiler.
If for instance you had a very small pipe going to the boiler, you may still get 21mb, conversely if you had a large pipe you would still get 21mb. The difference being that the large pipe can deliver a lot more gas at 21mb than a small pipe can. So the size of pipe is important. And of course making sure there is nothing blocking the inside of the pipe. I am afraid it is all to common for the likes of plaster to fall down pipes when left open while other trades work in the areas surrounding them. Also solid joints are not uncommon if to much solder has been used.

The usual pressure is 20mb coming out the meter with a permissible 1 mb drop at the appliance. I can't comment on the pipe sizing without a lot more information but just supposing its okay, then why is the boiler not firing?

I assume any air has been released out the gas line? I would have a few bob for every time I had tried to start a boiler on a new install without checking that.

Then of course you have to have a meter that will deliver the required amount of gas for all the flats. The problem is you still need 20mb in the loft with all the other gas appliances turned on. If the pipe is to small or the meter too small you will struggle to get that probably. You can get bigger meters of course but you may come on a different gas price rate if the meter is required to be overly big. It also depends on a few other things as well such as incoming mains sizes and pressures. So its not easy to give you a proper answer. Incidentally I think the meter comes under customs and excise as well as the supplier. I can assure you you do not want customs and excise after you for connecting in the gas main before they have metered it for VAT on the gas.

Try turning all the other gas appliances off in all the flats and then try the boiler. That at least may tell you that the pipe run to the boiler may be okay. What you are actually doing of course is running one boiler off the meter and the meter should be able to cope with that. If the air has not been purged, you can do it yourself by continually firing the boiler until you get a light or if it has a manual gas valve holding the button in flicking the piezo until the pilot light lights. It may take sometime as well, I must admit though the installer should have already done all this for you. Anyway if I can help just post some more and I will try to be a bit more specific.

 

[Millsy 82]

It does seem a bit of an unusual problem. Basically you are looking at two problems I suppose, if you are getting 21mb at the boiler.
If for instance you had a very small pipe going to the boiler, you may still get 21mb, conversely if you had a large pipe you would still get 21mb. The difference being that the large pipe can deliver a lot more gas at 21mb than a small pipe can. So the size of pipe is important. And of course making sure there is nothing blocking the inside of the pipe. I am afraid it is all to common for the likes of plaster to fall down pipes when left open while other trades work in the areas surrounding them. Also solid joints are not uncommon if to much solder has been used.

The usual pressure is 20mb coming out the meter with a permissible 1 mb drop at the appliance. I can't comment on the pipe sizing without a lot more information but just supposing its okay, then why is the boiler not firing?

I assume any air has been released out the gas line? I would have a few bob for every time I had tried to start a boiler on a new install without checking that.

Then of course you have to have a meter that will deliver the required amount of gas for all the flats. The problem is you still need 20mb in the loft with all the other gas appliances turned on. If the pipe is to small or the meter too small you will struggle to get that probably. You can get bigger meters of course but you may come on a different gas price rate if the meter is required to be overly big. It also depends on a few other things as well such as incoming mains sizes and pressures. So its not easy to give you a proper answer. Incidentally I think the meter comes under customs and excise as well as the supplier. I can assure you you do not want customs and excise after you for connecting in the gas main before they have metered it for VAT on the gas.

Try turning all the other gas appliances off in all the flats and then try the boiler. That at least may tell you that the pipe run to the boiler may be okay. What you are actually doing of course is running one boiler off the meter and the meter should be able to cope with that. If the air has not been purged, you can do it yourself by continually firing the boiler until you get a light or if it has a manual gas valve holding the button in flicking the piezo until the pilot light lights. It may take sometime as well, I must admit though the installer should have already done all this for you. Anyway if I can help just post some more and I will try to be a bit more specific.

Or you could test working pressure at meter. If you have 21mbar at meter working and nothing at boiler it will not and can not be air in the pipe as the air will be replaced from gas coming through the meter at between 19-23mbar (21mbar+/- 2) if the other appliances are working it may be that they use alot less gas. An old vaillant vcw gb 242 eh runs at 6.0 mbar high flame so would cope with undersized pipes better than an ecotec plus 831, But if the pressure drops to zero and you have working pressure at meter it will be blocked.

Also if you try to purge a gas pipe through a pilot be prepared to wait a long time. ( there is a proper way to purge but I wont say it here)

 

[AWheating]

Having read the further info you've now posted I would suggest taking a working pressure on the original boiler, if this is fine then you can rule out anything wrong with the existing meter and regulator. Then turn off all appliances except the new boiler and see if it fires. If standing pressure is 21mb but drops to zero when it fires it would suggest to me that there is a blockage/restriction in the new pipe run.

this should be common sense to any gas engineer. This engineer is either an idiot or not a gas engineer??

 

[sara275]

hi all

i can't thank you all enough for the info you have provided so far. Its a lil late now so i cant contact him to get any more info but will hopefully get onto it tomorrow to have him answer/ consider the points mentioned.

i'll sleep a bit better tonight knowing i've had second opinion from some great guys!!!

thanks again

 

[diamondgas]

this should be common sense to any gas engineer. This engineer is either an idiot or not a gas engineer??

:iagree: first school basics you'd hope :iagree:

 

[Resolute]

Good luck and let us know how it goes.

 

[AWheating]

hi all

i can't thank you all enough for the info you have provided so far. Its a lil late now so i cant contact him to get any more info but will hopefully get onto it tomorrow to have him answer/ consider the points mentioned.

i'll sleep a bit better tonight knowing i've had second opinion from some great guys!!!

thanks again

we are here to help

honestly tho, if your engineer needs his customer to ask simple questions on the internet i would be worried about the work thats been done and everything aside consider a second engineer.

 

[diamondgas]

hi all

i can't thank you all enough for the info you have provided so far. Its a lil late now so i cant contact him to get any more info but will hopefully get onto it tomorrow to have him answer/ consider the points mentioned.

i'll sleep a bit better tonight knowing i've had second opinion from some great guys!!!

thanks again

It'd be nice to know the outcome of your issue Sara should you be willing to return to the lions den Were ***** cats really Good night :waving:

 

[stevetheplumber]

cant see why he is getting zero my first thought was he was using the wrong test point on a zero govenor but he wouldnt get 21mb standing on that

 

[Bernie2]

Yes it is a bit peculiar. I am not saying the problem is air although air will compress to give a pressure reading, but it will not ignite. Seemingly the pipe is connected close to the meter and runs directly to the boiler wihtout any branches off. I assume its at least 22mm without to many bends or restricitions so it should work. Unless of course its blocked. I find more information would be needed to give a closer guess. The idea of continually firing the boiler up is about all a none gas person can do without breaking the gas train to check air has been purged. It doesn't however explain why the pressure drops to zero, although a fast acting gas valve can do that. Its hard to find out there are so many ifs and buts.

 

[wheeto]

A U6 meter will supply about 64kW/hr ... Your guy if he's GSR will know all this.

64kW/hr? What sort of unit is that? Are you sure you're GSR?

 

[galaxy_plumbing]

Gas Meters - Information if any doubt Second row.

 

[northstar]

hi all

i can't thank you all enough for the info you have provided so far. Its a lil late now so i cant contact him to get any more info but will hopefully get onto it tomorrow to have him answer/ consider the points mentioned.

i'll sleep a bit better tonight knowing i've had second opinion from some great guys!!!

thanks again

Hi did you get the problem fixed ?

 

[diamondgas]

64kW/hr? What sort of unit is that? Are you sure you're GSR?

Yes is the short answer to your question but here's the long hand answer:

U6 meter - 6m[SUP]3[/SUP]/hr of gas

Here's the maths wheeto:

Heat input = (Gas Rate x Calorific Value of gas)/3.6

or

(6 x 38.6)/3.6 = 64.33 kW/hr

A U6/E6 meter will therefore supply appliances up to the value of 64kW max guaranteed! Any more than that required for the property and you'll require a larger gas meter!

 

[wheeto]

Yes is the short answer to your question but here's the long hand answer:

U6 meter - 6m[SUP]3[/SUP]/hr of gas

Here's the maths wheeto:

Heat input = (Gas Rate x Calorific Value of gas)/3.6

or

(6 x 38.6)/3.6 = 64.33 kW/hr

A U6/E6 meter will therefore supply appliances up to the value of 64kW max guaranteed! Any more than that required for the property and you'll require a larger gas meter!

Thanks for the maths, but you still got the unit wrong ... it's 64kW, not kW/h.

 

[diamondgas]

Thanks for the maths, but you still got the unit wrong ... it's 64kW, not kW/h.

That's kind of sad that you'd question someone's GSR credentials on something so trivial! Hohummmmmm You're most likely right too wheeto but it detracts from the point I was getting accross to the op! Give yourself a pat on the back though for knowing your kW from your kW/hrs :clap:

 

[wheeto]

That's kind of sad that you'd question someone's GSR credentials on something so trivial! Hohummmmmm You're most likely right too wheeto but it detracts from the point I was getting accross to the op! Give yourself a pat on the back though for knowing your kW from your kW/hrs :clap:

Sorry. I'm sure you know I wasn't genuinely questioning your credentials - hence the emoticon in the first post - but everyone has pet peeves and one of mine is meaningless* units

Anyway you're right ... it's not helping the OP!

*OK, technically I suppose kW/hr is a unit of rate of change of power, struggling to find an application though.

 

[mountainman]

It seems the OP has left the building!

 

[Resolute]

It seems the OP has left the building!

We obviously weren't helpful enough or didn't tell them what they wanted to hear!

 

[Billy Bob Bob]

it sounds simple fault to me,if there getting 21 at the boiler but its dropping to zero when theres a a demand the governors shot

 

[Resolute]

it sounds simple fault to me,if there getting 21 at the boiler but its dropping to zero when theres a a demand the governors shot

I'd say this too except the problem only occurs on the new boiler and not the existing one.

 

[Billy Bob Bob]

I'd say this too except the problem only occurs on the new boiler and not the existing one.

existing one could be standard efficiency new one band a zero governor,old one will work with a dodgy governor new one wont

 

[Simon F]

Yes is the short answer to your question but here's the long hand answer:
U6 meter - 6m[SUP]3[/SUP]/hr of gas
Here's the maths wheeto:
Heat input = (Gas Rate x Calorific Value of gas)/3.6
or
(6 x 38.6)/3.6 = 64.33 kW/hr
A U6/E6 meter will therefore supply appliances up to the value of 64kW max guaranteed! Any more than that required for the property and you'll require a larger gas meter!

does that take into account the diversity factor for meter sizing?

 

[AWheating]

i found it hard that some even posted suggesting what to test and look for without the OP showing any knowledge or competence. I know its hard to judge and we all give information out in good faith. You get shot down if you question people who in escence are strangers.
For all we know its somebody whos done the work themselves and is up tit creek now it does not work and nobody they have phoned will touch it. who knows?? you cant always believe what somebody has posted on the internet, if you read my online dating profile im 6ft5 and hung like a horse...... sadly only one of them is true

 

[Bernie2]

My view is that most people know about Gas Safe engineers being required. They also know that if they are not competent they should not touch it even if it is in their own home. If they do not know that, then what are Gas Safe doing to promote safety?

One has to assume they do know the law. So there would appear little harm in telling them how things work. At some point you have to trust people to behave in a proper manner. After all you can watch doctors at work on the telly some even show you in detail. But do you go out and and operate on people?

 

[SimonG]

My view is that most people know about Gas Safe engineers being required. They also know that if they are not competent they should not touch it even if it is in their own home. If they do not know that, then what are Gas Safe doing to promote safety?

One has to assume they do know the law. So there would appear little harm in telling them how things work. At some point you have to trust people to behave in a proper manner. After all you can watch doctors at work on the telly some even show you in detail. But do you go out and and operate on people?

Nice analogy but imho not relevant as you wouldn't drop out your own appendix to save a few quid. I would like as you say to trust people but it is sometimes difficult.

I don't do gas, but would like to think if I did, and legally, I would know what to look for in the op situation without the cust having to trawl the internet to find a resolution. Even if i was stuck I would like to think I 'knew a man who could'. Something just seems off, but then that could just be the paranoia setting in, who said that

 

[M.Joshi]

With so many crooks and so-called GSR people around, people (like myself) come on here to obtain the correct information so that we are not fobbed off and are better informed.

If you're not happy giving advice in an open forum to the public then stick to the exclusive GSR forums.

 

[AWheating]

unfortunately although people know the law and right and wrong it will not stop them for what ever reason doing as they please. As a profession we should atleast try our best to avoid giving irresponsible advise. You cant control what people do with any information you give them, but you can try your best to avoid giving information when there is doubt about the legitimacy of the person or questions.

I cant see why some posters get upset when they get questioned about the reason's behind the posts, if they want an honest, safe and informative answer then why be defensive? some members even get upset and LIKE any post that seems to even question another member just because they dont like what was said in one post ( you can see patterns from some members and its petty)

ask yourself this. If the original post said ive fitted my own boiler and it wont work, please tell me how to fix it myself? what would your answer have been? i suppose atleast id like them more for the honesty.

 

[AWheating]

With so many crooks and so-called GSR people around, people (like myself) come on here to obtain the correct information so that we are not fobbed off and are better informed.

If you're not happy giving advice in an open forum to the public then stick to the exclusive GSR forums.

why do people need to ask detailed gas related questions if they are not either GSR or learning/training to be?? why do you need to be better informed about these things unless it relates to your job or future job??

if you cant see the argument that caution is needed when giving advise about such things and its not unreasonable to question some people then im lost

 

[M.Joshi]

I agree caution is needed but people come on here to be better informed because they have been stung/fobbed off in the past and also some of the tosh that some GSR people say when you speak to them to obtain quotes for repairs etc. - I don't mean that about most forum members on here who seem to know their trade well.

It's good to be better informed so that you know that the plumber/GSR person doing the work for you isn't fobbing you off.

I may ask technical questions but that doesn't mean that I will carry out gas work myself! I am just interested to find out the correct answer/solution.

 

[AWheating]

I agree caution is needed but people come on here to be better informed because they have been stung/fobbed off in the past and also some of the tosh that some GSR people say when you speak to them to obtain quotes for repairs etc. - I don't mean that about most forum members on here who seem to know their trade well.

It's good to be better informed so that you know that the plumber/GSR person doing the work for you isn't fobbing you off.

I may ask technical questions but that doesn't mean that I will carry out gas work myself! I am just interested to find out the correct answer/solution.

Iunderstand what your saying and agree that its probably a good thing to be well informed. You have to draw a line tho, giving technical answers or advise on how to test for things is not needed for a customer to be well informed. There has to be a line drawn in the sand between customer and engineer (trainee incl) when you give answers imo. If you have a customer having to go onto a internet forum to ask questions for her/his engineer the only real answer is to get a better engineer. If you was a customer and your engineer asked you to try and find answers you should be worried.

i cant say i have never given answers to poeple i wished i didnt, but im slowly learning its advisable not to if im unsure. Some posts are blantently a diyer wanting to work illegally. Some you just dont know and take a judgement, we are human afterall.

Im perfectly fine with tradepeople who want to learn and advance there knowledge asking questions, i myself wanted to understand electrics so went to college for 4.5 years to learn it. During that time i probably peed off pleanty of sparks asking question after question .

Reading posts and listening to customers it opens your eyes to how poorly the trade is viewed in many peoples eyes, the only gas engineers you see on tv are one ripping off customers because it sells and brings in viewers. Many customers expect to be stung as you put it, so as engineers i guess we all have some part to play in trying to lift the opinions of the trade. So even tho this is just an open forum maybe we ow it to ourseves to answer questions professionally. What exactly is the best way to do this is up for debate. You get accused of being a rip of merchant when you disconnect a dangerous appliance, or a wazock for suggesting somebody gets a competent person in..... sometimes you cant win,

i need a beer.

 

[AWheating]

With so many crooks and so-called GSR people around

this is one reason why i question giving answers in open forums, this is what many customers are thinking before they phone you up about work. Am i answering a question to an ilegall fitter? if so am i only helping make the above statement more true. but on the flip side the more we discuss technical issues and the more we all learn and become better engineers the better. Its a hard balance i must admit.

 

[Bernie2]

The problem is the questioner could find all the answers out, simply by buying a book, looking at MI's or going down to their main library and reading the relevant BS document for free. I like to think the person who I am doing the work for knows as much about the job as me. Then you get mutual understanding of what is involved. It is not necessarily that they will go away and work illegally. It is like speeding, it is entirely up to the driver if they decide to do so, but I would not stop a person from learning to drive just because they might speed. Its the same with a gun, having the knowledge or giving the knowledge about how to fire one is perhaps harmless, it is only when a nutter decides to kill that they become dangerous.


I can appreciate the point your making and to a certain degree I agree with you, but what if the person knows little about what they are doing but still decides to do it? Surely that is far more dangerous? As a young man I thought flying a glider looks easy, but when you learn what is really involved its a whole new game and you realise it isn't.

 

[mountainman]

I don't suppose this thread would have originated had the OP employed an engineer off of the Gas Safe website.