mains water temp

[buckley plumb]

was called to inspect a barn conversion where the mains had been taken from stoptap to cylinder cpboard and lagged up to there but then it come out of the cylinder cupboard to all the cold taps including kitchen tap unlagged. the problem is the pipe runs in the floor void with the under floor htg.the customer is complaining of warm cold water untill he emties the water in the section under the floor.what are the rules for drinking supply water .i thought it was you were allowed to run tap to purge for 1 minute then test temp and if less than 20degrees then its ok. am i right

thanks ant🙁

 

[justlead1]

Hi. Running a mains feed tap for 60 seconds on 15 mm pipe at say 4 bar pressure is likely to waste 50 litres of water! Seems like a lot of water before acceptable temp is reached. Re-routing the pipe seems to be a must?

 

[PlumbBobBob]

agree with justlead main consideration these days is to avoid wastage best to reroute pipe to avoid ufh

 

[Gray0689]

A cold water pipe should not be anywhere near underfloor heating should be at least under any insulation i'd hate to see what else the Plumber has done under that floor

 

[buckley plumb]

there is 4 barn conversions like this .mains into building is 6m away from kitchen sink in some of them. the ceiling void is full of rock wool so its a ceiling down job looking at it .i would not be happy if i had just spent nearly 1million on a barn house would you.builder is looking for a quick fix but i dont think there is one .chillers were mentioned but they will only hide the problem.

ant

 

[wiseman]

how bigs this floor void?

 

[buckley plumb]

how bigs this floor void?

about 8" cut part of ceiling and found underfloor pipes clipped to floor panels then a thin layer of foil then the cold and hot pipes and any gap filled with rockwool. manged to feed a cold supply from the cloak ceiling to the kitchen sink drop in the kitchen ceiling so at least the kitchen sink has cold water.builder not intrested in correcting anything else due to cost

ant

 

[Timbob]

Cold water mains should not reached higher than 25 degrees C. simples.

Should always be lagged in any unheated and/or draughty areas or where touching or fixed to cold surfaces. Should also be lagged anywhere that there may be a chance of it getting warmed.

 

[martin b]

cold water should not be more than 20 degrees, water regs say 25 degrees but this is overruled by legionella rules in BS 6700

 

[aqualogic7]

sorry water regs overrule legionella rules as water regs are an act of parliment

 

[prs1]

25 degrees is the maximum temp that the water supplier can supply the water at!

ACOP L8 recommends Mains cold water be at a temp of 20 degrees or under after 2 mins!

The issue in reality is covered in BS6700- As said previously the pipework should be sufficietly insulated to stop any heat transfer.
If the propertys are recent builds then i would be speaking to the builder to sort the issue as we all know that minimum standard should satisfy BS.
ACOP L8-Is compiled from water regs and BS but does have other recommendations aswell to ensure that water systems operate correctly.

 

[rocketmanbkk]

yep, water regs state 25 and building regs 20 degrees

 

[billybob150811]

agree with prs 20 degrees in 2 min basic army spec lagging may not help it slows down heat gain but when your timing the cold water temp it prevents the temp falling
measure the temp of the tank of cold water its what your hoping will cause the temp to fall no easy answer to this