Gas pressure problems, use of MDPE pipe outside?

[AWheating]

incorrect sized pipework on a new install spells cowboy plain and simple, if that how you work then giddy up!

 

[Halesowen1]

we all know the regs state 1mbar drop between meter and appliance. it's outdated though.
if i can prove a premix burner is working to full performance with correct GR/HI , temp rise on DHW, CA values, no affect on safety of any other appliances, as a gas engineer i m happy as larry. if it s not performing to full performance and is undergassed , then it gets upgraded . thats engineering judgement , and no reg is going to tell me a boiler operating perfectly on a 22mm supply is going to work better on a 28mm

suppose yous all always calculate the IV of the pipework for purging as well lol

tamz knows the script , watch out for a TB on coming soon

When the reg is outdated I am sure it will be changed, untill then its best to stick to them. Do you note on your gas cert for the boiler that the Brand New Boiler you have just fitted for the customer is Not to Current Standards?? (You cannot fit a new appliance not to current standrads, that rule is for existing)
No you dont.............. So then you are getting deeper in it.

 

[< 0.004 = :-)]

last cdi i fitted was a 37cdi badged as a BG537i , it has a bit in MIs about the pressure drop through the gas valve =1.5 , so 18 - 1.5 = 16.5 is acceptable. they haven t updated the MI that you download from their site yet

Worcester TB 40 and gsr TB 129 , think i v got the installer mag with the article TB 40 refers too, corgi still send it out for free to ex members. if i can dig it out i ll scan it and post it.

 

[< 0.004 = :-)]

incorrect sized pipework on a new install spells cowboy plain and simple, if that how you work then giddy up!

lol , yeeeeehaaaaa
cowboy s needlessly cost the customer money because they have no clue about gas engineering , and simply follow what the book tells them rather than apply basic engineering.

 

[Halesowen1]

last cdi i fitted was a 37cdi badged as a BG537i , it has a bit in MIs about the pressure drop through the gas valve =1.5 , so 18 - 1.5 = 16.5 is acceptable. they haven t updated the MI that you download from their site yet

Worcester TB 40 and gsr TB 129 , think i v got the installer mag with the article TB 40 refers too, corgi still send it out for free to ex members. if i can dig it out i ll scan it and post it.

I dont get what you are trying to say here, that 16.5MB is OK?? Not if its 22MB at meter mate, then you would be getting 5.5MB drop when you are allowed 1mb plus what Worcester allow now for valve. But max up to 2.5mb deffo not 5.5mb

 

[Halesowen1]

What you are quoting is minimum working pressure, and yes we know that. We are talking about pressure drop from meter to boiler, 1mb max allowed. So yes your boiler can be Ok working at 16.5mb plus the 2,5mb allowed for drop and valve, but then the meter must be only giving 19mb. But what if its 20,21,22,23mb??

 

[AWheating]

not that it matters as whatever the MI say more than 1mb drop in wrong but the WB manual states 18mb (fitted a 30cdi last weekend) at the test point on the gas valve. If you allow 1.5mb drop from appliance gas iso cock to this point then the min required pressure is 19.5mb on entry into the gas iso valve at the bottom of the boiler. with 1mb drop across pipework and you need 20.5mb working pressure at the meter.

as for the worcester tb40 if i remember it discusses issues with high peak times and operation of its boilers within these low pressure periods.

no need to post me anything, i get the corgi mag, the gas safe mag, the worcester mag.... as you are a cowboy you can send me a copy of horse and hound lol.

 

[tamz]

TB40
http://www.worcester-bosch.co.uk/cache/file/20/minimum-gas-operating-pressure.pdf

The boiler manu's know fine well what their boilers will work on. The 1.5mb permissible drop through the boiler is a bit of a smokescreen imo.
I've fitted many where the difference between the wp at the meter and at the test point on the gas valve is less than 1mb. If it can get through some with very little drop then why not others?
The only way to confirm the drop on the pipework is to cut a test point in as it connects to the boiler. Very few do that, for obvious reasons.

 

[AWheating]

lol , yeeeeehaaaaa
cowboy s needlessly cost the customer money because they have no clue about gas engineering , and simply follow what the book tells them rather than apply basic engineering.

please explain these things to you Gas Safe inspector and maybe he will redraft the regs to suit your needs.

 

[AWheating]

TB40
http://www.worcester-bosch.co.uk/cache/file/20/minimum-gas-operating-pressure.pdf

The boiler manu's know fine well what their boilers will work on. The 1.5mb permissible drop through the boiler is a bit of a smokescreen imo.
I've fitted many where the difference between the wp at the meter and at the test point on the gas valve is less than 1mb. If it can get through some with very little drop then why not others?
The only way to confirm the drop on the pipework is to cut a test point in as it connects to the boiler. Very few do that, for obvious reasons.

i agree def smokescreen and anybody relying on the 1.5mb get out of jail free card to cover there undersized pipe needs to rethink what they are doing.
Tested a 30si friday and i got 20.2 at the boiler and 21 at the meter, no 1.5mb drop in sight.

 

[Halesowen1]

Worcester boilers are probably the best for this, you dont get many Worcester boilers with more than 1mb drop anyway. Ideal are horrendous, I fitted one of these within 2m off meter, 22mm x2m and it dropped 2mb. Rang Ideal and they told about new allowed drops through valve.

 

[Halesowen1]

I dont think it is a smokescreen, some boilers like Worcester dont lose any through the valve, but others do and lose 2mb.

 

[AWheating]

well its a smokescreen because some engineers use the figure to justify poor work and having 16.5mb WP. If i was a customer who's 1 year old boiler had a NCS/warning notice on its anual service i would not be to impressed.

 

[< 0.004 = :-)]

When the reg is outdated I am sure it will be changed, untill then its best to stick to them. Do you note on your gas cert for the boiler that the Brand New Boiler you have just fitted for the customer is Not to Current Standards?? (You cannot fit a new appliance not to current standrads, that rule is for existing)
No you dont.............. So then you are getting deeper in it.

you can install a new appliance ID, never mind ncs if you don t know what your doing. had an LLSC y-day on a property with a new boiler fitted in june. 2mbar drop on an e6. asked tenant if any whiffs of gas, yeh sometimes in the kitchen where new boiler fitted. traced it to leak at the isovalve,. olive squashed into fitting. repaired it and completed the cp12. riddoring aint for me though, leave that to the gas polis.

gas cert for the boiler ? we don t need to notify in Scotland.
fill out the commisioning sheet , with GR/HI, IP/WP and CA results blah blah .
not a chance WB,BG,Vaillant or any large co., who can afford to employ expensive lawyers would leave theirselves exposed by not condemning appliances operating perfectly with lower than stated WP. if there was the slightest safety issue , they be AR-ed to CTA.

do you think gsr are going to come after you if you can prove a boiler is operating safely and to full performance , with more than a 1mbar drop ? they would laughed out of any court.

 

[< 0.004 = :-)]

say this one more time , but i doubt the penny is going to drop here .
the 1mbar drop is an outdated reg , from the days of se pre aerated burners.

i m mainly talking about replacing existing se combis with condensers. when going by the book , the gas should be at least kicked off in 28mm. houses that have finished hardwood floors throughout. a total nightmare to upgrade to acheive max 1 drop. and with 4 appliances , meaning a 20m run from meter now becomes an 80m for your calcs to acheive max 1 accross whole installation with everything running at max if we re doing it right (that bit confuses a lot of fitters) and not being cowboys remember, the costs become frightening.

if a boiler with a pre-mix burner works to Manufacturers spec ie , Gas Rate is Spot on , CO2/Co ratio, DHW temp rise etc on an existing supply (swapping standard for condenser, combi-combi) why would you insist on upgrading the gas first ?
would you not say to customer , going by the calculations , i may have to upgrade the gas to acheive a 1mbar max drop to fully comply with current regs blah blah, but this will involve upheaval and expense. the alternative is to install the boiler first , carry out checks, if not acheiving full permormance and it s undergassed i will need to upgrade it. if however it does not require upgraded to achieve full performance, even though your calculations tell you different , then obviously the calculations are costing your customers money they do not need to spend and you are the cowboy Matt Albright is more likely to take an interest in , than the sensible engineers taking he logical approach.

 

[< 0.004 = :-)]

Worcester boilers are probably the best for this, you dont get many Worcester boilers with more than 1mb drop anyway. Ideal are horrendous, I fitted one of these within 2m off meter, 22mm x2m and it dropped 2mb. Rang Ideal and they told about new allowed drops through valve.

new ideals and glow worms have a test nipple on the isovalve , takes away any doubt. bit nippy if boilers been boxed in underneath though, joiners , aaarrrrgggg lol

 

[Halesowen1]

So basically you are saying that you are not going to abide to Gas Reg's??
Well you go ahead.
P.S Looks like your horse needs some water...................

 

[Halesowen1]

If its an outdated regulation I am sure it would have been amended or removed. As all us fitters know the reg's can change from day to day.
But again i will say it, if you want to carry on breaking reg's then do so.

 

[fuzzy]

op says we cannot run bonded pipe outside, so its all academic.........mmmmmmmmmmm

 

[mikimac]

op says we cannot run bonded pipe outside, so its all academic.........mmmmmmmmmmm

If that's the case we should all be rushed off our feet 'cos there's plenty of it around...prepare for a payday guys n gals :rolleyes4:

 

[< 0.004 = :-)]

So basically you are saying that you are not going to abide to Gas Reg's??
Well you go ahead.
P.S Looks like your horse needs some water...................

lol , 20 odd years in the game mate, this thread is the first time i v been called a cowboy.
rollin , rollin , rollin

i don t set out to break regs and always try to follow them , but sometimes a bit simple common sense, experience and engineers discretion are also required.
so do you calculate IV for purging on every install ? if not then you must be a cowboy , no?
i know you would ve been delighted to find a gas leak on an inspection and riddor the installer, who would ve probably lost his job. if i knew him i d have gave a phone, but i aint going to grass him up. it may actually have held a TT when the job was completed, who knows. it was a very small leak, couldn t find it with LDF, traced it with the sniffer, the tenant must have a great sense of smell. 8mb permissable on an exsiting with E6 and appliances connected (its 6 month old, i did not install it so its existing), and no i wouldn t leave a new install of mine with any drop. we re gas engineers , not the polis, shouldn t fall on us to grass up other engineers.

 

[tamz]

If its an outdated regulation I am sure it would have been amended or removed. As all us fitters know the reg's can change from day to day.
But again i will say it, if you want to carry on breaking reg's then do so.

It is an outdated regulation and will be changed. The British Standards don't change from day to day, they take a long time and a lot of consultation before they do.
The current 6891 was published in 2005. Band A's were not the norm then.
ZPG's have changed a lot of things and ways of thinking.

 

[AWheating]

Changing the regs to suit one type of appliance would need very careful considerations as it could lead to many poor installations. Many engineers dont need any more excuses to avoid altering gas pipework and i would expect to find more installations with appliances competing against one another which could have major problems when appliances without fsd's are starved. I guess we will see what happens.

 

[tamz]

I guess we will see what happens.

That is true.
Cleverer people than us decide what is best.

 

[fuzzy]

If that's the case we should all be rushed off our feet 'cos there's plenty of it around...prepare for a payday guys n gals :rolleyes4:

yes there are many, im waiting for op to clarify his statements, he has agreed to do so without fear of prosecution