upgrading water main for unvented?

[mike_s]

Where do you upgrade to 22mm? Do you advise the customer to contact local water authorities to upgrade it in the street if feasable?

 

[SafeGasInstall]

you do not need to contact them ( I think) you just go for 25 MDPE if is up to 20m if is longer run go for 32MDPE and you pick up from the stop tap on the street ! If stop tap is faulty then you need to speak to water authorities ! get some builder to dig it up as it could be well dangerous when start digging on my last job the went trough gas pipe ,nearly miss bt cables and some other waist pipe

 

[AlexGas]

There’s a way to calculate the mains pipe size for a house.
As said above - 25mm should do it.

 

[AWheating]

have you measured the flow rate and pressure at the incomming stop tap?

 

[mike_s]

I havn't been to it yet but been told it's very good, if it's over 3 bar and 20 litres per minute, could I just upsize to 22mm from the stop tap inside the house if the customer doesn't want the work to be done outside?
Are we even allowed to work on the pipe before the stop tap?
Also, could anybody help me with the water main sizing calculations please? I have my unvented ticket, gas safe registration, ive done nvq's to level 3 in plumbing and gas and have 7 years experience but this is new to me, thanks.

 

[mikegas]

If you have 3 bar an 20lpm crack on, 22mm to cylinder

 

[AWheating]

I havn't been to it yet but been told it's very good, if it's over 3 bar and 20 litres per minute, could I just upsize to 22mm from the stop tap inside the house if the customer doesn't want the work to be done outside?
Are we even allowed to work on the pipe before the stop tap?
Also, could anybody help me with the water main sizing calculations please? I have my unvented ticket, gas safe registration, ive done nvq's to level 3 in plumbing and gas and have 7 years experience but this is new to me, thanks.

if you have even 2 bar and 20plus lpm you should be ok unless its a very big house with high demands? once you have calculated you hot water demands and cylinder size contact the manufacture or download the instructions and you can find what the min flow and pressure requirments are.

if all is good run 22mm to cylinder and balance cold to a/c.

the pipe from the houses boundary to inside the house will belong to the land/home owner so its there property to fix/replace if needs be. The water board would have to connect anything outside the boundary one there side.

the correct water main is the one that supplies the right amount of water for the buildings demands, if you have that already then dont worry.

what size is the house and what are the hot and cold demands?

 

[mike_s]

Thanks, very helpful reply, I'll definitely be speaking to the manufacturers on the sizing to confirm before I give a price for anything, the house is having building work done, I think it will end up with 2 bathrooms and 2 en-suites, just 2 showers off the cylinder so should be no problem, I'll go for a 250- 300 litre as theres 4 living in the house and there's plenty of room.
I will make a balanced cold connection for all outlets, I'm glad I don't think I'll have to upgrade the water main in the street as the main stop tap is in the same room the cylinder will be so taking 22 straight to the cylinder will be easy. Thanks.

 

[AWheating]

fitting flow restrictors in the shower supplys can help keep flowrates evened if you think it may help. also good for bills/enviroment