How much space required for this plant room?

[doitall]

Gaswhizz, its not the cost standing in the way. Its the fact that tge person who came to give me a quote said it was't needed and that my gas supply wouldn't handle it

The only person to answer that would be the gas transporter.

Phone them up and ask if they could supply a larger meter without digging the drive up.

The service pipe should be 75mbar ish, but there's several reason it could be a lot less, whatever your plumber can't test it.

In light of recent developments You're best bet now would be to see what Alec has to say.

 

[gaswizzard]

1) One 300l unvented cylinder, or one 400l max. In terms of two cylinders he says that my gas supply will only handle my current 30kW boiler and then an additional 24kW one. On this basis he says I won't have the boiler capacity to match the coil ratings of two cylinders, so no point. (Also standing losses would be greater)

U6 meter will pass 6 m3/hr with a rating of 64kw (input) , has he tested? , two 300 litre cylinders will each have a coil rating of 'around' 22kw so two 25 kw boilers should be no problem fed from a U6.

 

[SimonH2]

To answer Simon since he want another pop at me as per usual.

I wasn't having a go at you at all, just pointing out that whoever the OP asks, they will have a method they believe will do the job, and will be quite ready to state just how wrong any other method is. Seen it many a time, and there tends to be that "sucking" that some tradesmen seen to have spent much time perfecting. How many times have we come across that "wouldn't have done it that way" attitude ? Even in this one thread there's been multiple opinions as to how it shoul be done and why all the other suggestions are wrong

It was only partly tongue in cheek. And it wasn't aimed at anyone in particular - however if someone is feeling guilty and thinks it describes them ...

Gaswhizz, its not the cost standing in the way. Its the fact that tge person who came to give me a quote said it was't needed and that my gas supply wouldn't handle it.

Hmm. The gas supply limits how much gas you can draw, and therefore how big your boiler(s) can be. That doesn't directly limit how much or how fast you can draw off hot water - unless the supply is very limiting - but it does determine the recovery time and the quantity of storage needed.
The limit would be where you had to run a boiler at the limit of the gas supply capacity for 24hr/day. In principal, if the boiler could recover in 23 hours then the system would work but you'd need enough storage to cover pretty well all your needs - the boiler would catch up during the day when you're out and while your asleep at night. In reality such a system would be daft unless it really was the only option.
More likely is that a limited gas supply would mean the difference between (say) one hour and two hours to reheat the cylinders. Even for that difference, it has an impact on how much hot water you need to store since you can reheat a significant amount of water during/between showers if recovery time is only one hour (and the system is designed for that).

 

[indus]

Gaswhizz, its not the cost standing in the way. Its the fact that tge person who came to give me a quote said it was't needed and that my gas supply wouldn't handle it

The only person to answer that would be the gas transporter.

Phone them up and ask if they could supply a larger meter without digging the drive up.

The service pipe should be 75mbar ish, but there's several reason it could be a lot less, whatever your plumber can't test it.

In light of recent developments You're best bet now would be to see what Alec has to say.

I don't understand. You've said a number of times in no uncertain terms that the standard gas supply is no problem. Now it seems like you are saying that it can't be taken for granted and is a question only my gas supplier can answer. Even that my drive might need to be dug up.

Not trying to be funny dia, but is a standard domestic gas supply capable of serving the two coils in two large cylinders or not?


Thanks again

 

[indus]

1) One 300l unvented cylinder, or one 400l max. In terms of two cylinders he says that my gas supply will only handle my current 30kW boiler and then an additional 24kW one. On this basis he says I won't have the boiler capacity to match the coil ratings of two cylinders, so no point. (Also standing losses would be greater)

U6 meter will pass 6 m3/hr with a rating of 64kw (input) , has he tested? , two 300 litre cylinders will each have a coil rating of 'around' 22kw so two 25 kw boilers should be no problem fed from a U6.

GW

Can I assume I have a U6 meter, how do I confirm?

Thanks

 

[gaswizzard]

The meter will will be badged at either a U6 , G4 , 212 or E6 , these are all domestic meters which pass 6 M3/hr , if you took the trouble to read the posts we wouldn't have to keep repeating ourselves (6m3/0.094 = 63kw)

You are trying to learn the plumbing/heating trade to which it's impossible on a forum like this , you'll end up with more questions than answers , maybe go treat yourself to a 6 week plumbing course.

 

[doitall]

I don't understand. You've said a number of times in no uncertain terms that the standard gas supply is no problem. Now it seems like you are saying that it can't be taken for granted and is a question only my gas supplier can answer. Even that my drive might need to be dug up.

Not trying to be funny dia, but is a standard domestic gas supply capable of serving the two coils in two large cylinders or not?


Thanks again

A standard service pipe should be able to supply your demands, with the right size meter, remember it's not just the boilers, so you may need the next larger meter.

There are odd occasions where the gas service pipe can be corroded, crushed etc so the pressure is restricted.

A call to the transporter will tell what it should be, and of course there's always a remote chance it will be to low.

 

[doitall]

Indus,

At the start of this thread and several times in between, I have made it quite clear, that the guy on site, needs to do all the tests and come up with a working design to suit the client. You should be sat down discussing not just the finer points but the whole project.

However that guys is no good if he doesn't do the test and makes it up as he goes, you can't assume anything in this trade.

As I said earlier have a chat with Alec, over spec if far superior to under spec, even if it costs another £rand.

 

[indus]

Thanks DIA/Simon/GW

I am listening and taking your comments on board, honest.

I tried to do exactly what you said, it's not my fault if a proposed installer tells me the gas supply is not up to the job (without measuring it) of two cylinders.

Thanks again

 

[mysteryman]

The gas transporter will be obliged to sort out the supply if it can't deliver 6m3/hr, so that's not a problem. I can't see why we are discussing two cylinders when one 500 litre with 70kW coils will do the job. My preference for the cold water supply would be a break tank and pump set, although if it is a multiple storey house, perhaps a large cold storage tank in the loft might to it, you know, the old way?

The other thing is to get more than one view and quote.

 

[doitall]

Mysteryman, I don't have a problem with your 500ltr cylinder if thats what yo prefer, my problem then and now is trying to flog Viessmann boilers and the all in one box technology.

The OP has a perfectly good boiler and just need a second boiler to compliment each other.

Two smaller boilers are cheaper to run more often than not, especially in the summer, and the important fact is they give back up when (not if) whatever boiler you use breaks down.

In a private discussion elsewhere, it seems a lot of RGI's are unhappy with Viessmann, especially their service, or lack of, department, waiting weeks for spares is not good unless you have a second boiler to keep the system ticking over.