Unvented mixer tap

[bikerbas]

Hi all i have a customer who wants me to fit a mixer shower on her bath,ive had a look and its a unvented sys.
Am i allowed to do the job because i would have to turn the water off and drain down the hot water.
Or is it a job for someone whos got unvented on the card
cheers

[justlead1]

Hi, Providing you turn of the energy source (immersion and or gas boiler) and water feeding the unit, i personally can not see a problem. Good Luck

[Zammo1001]

Should be no problem you didn't fit the unvented system so a drain down and would be ok on your part.

[bikerbas]

Cheers for replys
If i drain down will it need the pressure building up in the sys once the jobs done?

[Zammo1001]

The unvented runs off mains so no

[aggis]

Will need to fit non-return valves to both hot & cold

[bikerbas]

Cheers for that very helpfull

[Gray0689]

You don't need to fit non return valves turn off water drain at bath fit taps and turn water back on it's that simple

[gas man]

Will need to fit non-return valves to both hot & cold

they are built in to most thermostatic bar mixers

[oldplumber]

if the cold water supply is taken off the balanced part of the unvented syste you dont need non return valves. You only have to turn off the cold feed to the unvented cylinder, open taps to reduce pressure and off you go, trickle when you cut pipework, cylinder doesnt need draining down if thats what was being discussed earlier, may have missed something tho

[aggis]

You don't need to fit non return valves turn off water drain at bath fit taps and turn water back on it's that simple

If the H & C is unbalanced on an unvented system, best to fit them, as I have been recently dealing with many showers that are passing from cold to hot, therefore giving luke warm water. Agreed that balanced unvented dhw systems don't need non return valves & some mixer showers have them fitted [check MI ]
But if not sure what system fit non return valves, for @£5 it'll save you going back at your own cost.

[Gray0689]

The idea of un unvented cylinder is the hot and cold should be balanced if it is not it's fitted wrong

[aggis]

The idea of un unvented cylinder is the hot and cold should be balanced if it is not it's fitted wrong

Agree, But do the fully trained only work in the plumbing & gas industry!