Hi, Im going to be installing an unvented cylinder to a property next week. I've got the cert and hand books but I can't see any info on pipe sizing for the feed! The ones I've done in the past hve all had a 22 mm rising main, this one has a 15 mm. The pressure and flow rates are good. Will it have an effect on how the system will work? Or should I replace the cold pipe from the stop tap to the cylinder with 22mm pipe?
Currently reading:
Unvented cylinder feed pipe
Discuss Unvented cylinder feed pipe in the Plumbing Jobs | The Job-board area at PlumbersForums.net
S
sheff paul
thought you would have gone to bed
S
sheff paul
Sorry sir wont happen again
I had a tad over 4.5 bar and my wire gauge was in excess of 22L/m! It took me 26 seconds to fill 14L, so I'd have about 30l/m! Thanks for the responses, some were better than others! I thought I'd ask here as I've moved house and misplaced the manual I got doing my unvented training, mite look for it again tomorrow.
S
sheff paul
Top pressure/flow there mate ,be carefull not to get knocked over in the shower
K
kay-jay
Corgi do an unvented design guide which is pretty good. You may find it useful
- Messages
- 10,028
If the customer is fortunate to have a mains pipe that is easily accessible & therefore easy to replace, then it really should be taken right back to stopcock in 22mm. If mains pipe from outside is replaced in future, then flow will be improved.
The old pipe is often done with leaded solder joints, so good to get rid of.
15mm will be fine for a small one bathroom house or a home with low demand on water/or only one or two people occupying. Really depends on what customer wants or is prepared to pay. If flow & pressure are good & customer doesn't want the entire mains pipe replaced due to any possible upheaval or extra cost, then just change mains at unvented unit over to 22mm & go to hot & cold in 22mm, preferably all balanced.
The old pipe is often done with leaded solder joints, so good to get rid of.
15mm will be fine for a small one bathroom house or a home with low demand on water/or only one or two people occupying. Really depends on what customer wants or is prepared to pay. If flow & pressure are good & customer doesn't want the entire mains pipe replaced due to any possible upheaval or extra cost, then just change mains at unvented unit over to 22mm & go to hot & cold in 22mm, preferably all balanced.
Last edited:
Even the gas?
Youve answerd your own question really. 4.5 dynamic pressure is and a flow rate foo 30 is excellent.
Me personally in a kitchen would drop pipe work behind kitchen cupboard in the dab and then pipe up to boiler all drops straight down no horzi runs. Timber boxing tiled to match wall made removable for access. Too risky dropping behind boiler with risk of boiler and cupboard fixings etc.....
I agree with the 10mm to basin's but I would normally 1st fix in 15mm and reduce after doc and Isolation valves.
Last edited:
Company dont want anything on show and no boxings. Gonna cause all sorts of issues imo dropping all pipes behind boiler on first fix.
Can't remember the last time I've seen a kitchen fitted exactly to a drawing. At lease it's copper in the dab and detectable I guess. I'd be core drilling the boiler hole, make a timber templet of cupboard with boiler inside with all fixings and pipework points. If your lucky it's not a party wall so you can channel the pipes in 10-15mm so you don't need extreemely long screws to hold the boiler on or even make sure the dabs land near the fixing points.
Last edited:
- Messages
- 1,237
Recommend a 22mm feed. No more no less from the stop cuck, prior the feed would be balanced outlet to all of the other appliance after the composition or PRV,and knowing you won't have any Doubt over bath and appliances working at the same time .. 15mm is sufficient if you have good flow and standing pressure. But on higher demand
K
kay-jay
Have your g3 qualification then spanner?
E
Ermintrude
22 normally minimum. And mdpe above 25mm usually up here. Typical 3 to 5 bar 20 lpm at boundary.,
- Messages
- 1,237
C
Clive53
Q can a Honeywell 921 RF type room thermostat be fitted to a std boiler Glowworm 44FF i think. Control from a moving controller
Is this in the right place?
Is this in the right place?
E
Ermintrude
Yes but need a programmer too for DHW??
C
Clive53
It's a std boiler. The current room thermostat is in the hall and far away. I am looking for a mobile RF type where the control is in the main room wifi d to the base, which is wired into the control box
E
Ermintrude
Easy. Take cover off of thermostat in hall and post a picture of wires. Do you intend to fit a programmable stat ( never remember Honeywell model no's) if you are fitting a prog stat then either fit programmer on constant ch or bypass it ( I recommend you just put on constant)
Are you competent with a multi meter and electrics? If not get a spark/ plumber in.
Are you competent with a multi meter and electrics? If not get a spark/ plumber in.
E
Ermintrude
Wall stat isn't really a GSR issue is it? Built in one or one that requires the boiler to be touched yes. Room stat me thinks not?
- Status
Reply to Unvented cylinder feed pipe in the Plumbing Jobs | The Job-board area at PlumbersForums.net