Secondary Domestic Hot Water Return.

[SimonG]

Quick question on the above regarding doctors surgery. I've been replacing washbasins with vanesta's as aprt of an upgrade. Into the final 4 now which are in an extension that was done about 10 years ago. The plumber 10 years ago has screwed up royally, there was an old basin that had been removed and new one fitted and water services extended to a further 3 basins on the end of the run. This basin is fed through the wall from the basin on the other side and the return terminates just before the offtakes. The plumber has teed of the feed to this basin (on the new side) to feed the extension and then created a secondary return (all in speedfit must have had a job lot of fittings, everywhere). So this secondary return is just one 15m dead leg.

Obviously I am concerned at this, but don't know the chapter and verse to quote to the practise manager so that I can leave it all and be happy with it. The rest of the plumbing is spot on, apart from this extension, which looks very much like 'builders' plumbing.


Any assistance greatly received.

Simon.

 

[chris watkins]

Not quite sure what u r asking Simon but the normal arrangement with secondary returns is that the return should only connect to the HW F close to the furthest fitting on each run out so if the old F&R have been extended on to serve the new basins the return connection should have been removed or turned off.
You can if you have a number of run outs fit lock shields as balancing valves on each just like a radiator system.

 

[SimonG]

I know, I should have took a picture, but what they have done is extend the flow through the wall (no return) and then just created a useless return on the new side, rather than extending the return through also. If that makes more sense! I don't believe that it was done to regs and I don't want to leave it and then the finger come back to me as last man in. I have very little experience of secondary returns, I have to go back to my apprentice days on a large hospital contract. Through the mists of time I recall that outlet had to be within 300mm of loop, but may have my numbers wrong.

 

[chris watkins]

In hospitals may be but normal max of un-insulated HW pipe is I think 12M of 15mm or 22mm, so I am guessing in this case not too far so as long a the water at the furthest fitting gets hot within say 30 Sec it is OK.

 

[SimonG]

Cheers Chris, shame you had to mention the insulation, the hot, cold and hor return are all tie wrapped together uninsulated in the pipe boxing. Think I'll get all the boxing stripped out and put it all right.