DIY Doctor

Main navigation

To Pump or not to Pump?

Postby Big_Dave » Sat Dec 29, 2007 5:52 pm

I live in a single storey flat where the cold water to all appliances is mains. Hot water is via a gravity feed from a cold water tank in the flat (height to top of water in tank approx 2.3mtrs) into a copper cylinder with immersion heater. As you might guess, the flow is pathetic! I have bought a Stuart Turner Monsoon 2bar negative pressure pump to install via an Deleted Flange and insert in the system to pump all appliances per manufacturers instruction. So far so good.

My problem is that a "friend" has told me that he was advised not to pump a system where the pipework is over 3 years old or hidden in walls or concrete floors due to "Possible splitting of the pipe or joints blowing". My pipework is 25 years old, copper throughout and as far as I can see soldered fittings.

Do I heed his advice and put up with hot water dribble or go ahead!

Sorry for such a long post but I'm desperate!

All comments gratefully received.

Big Dave.
Rank: Labourer
Progress to next rank:
Posts: 3
Joined: Sat Dec 29, 2007 5:50 pm


Simply Build It

Postby htg engineer » Sun Dec 30, 2007 6:15 pm

Whats the other options ?

Are you planning on fitting a shower, or is it just for a bath and washing ?
Would an electric shower be better ?

If you're thinking about re-piping it, is it worth trying it first ?
all may be well. If not your only back to square one - having to re-pipe it.

Why don't you pressure test hot water pipework first, using a test tee, hand bellows and u gauge ?

Hope this helps,
htg engineer
Rank: Project Manager
Posts: 3256
Joined: Tue May 22, 2007 5:22 pm

Postby Big_Dave » Mon Dec 31, 2007 9:21 am

Thanks for your post.

The flat has 2 bathrooms, one with shower, WC and WHB, the other with bath with shower over, WC and WHB. Both the showers are Mira electric via mains supply so no problem. The problem area is the HW supply to the exixting 2 WHB's, the bath and kitchen sink.

Therefore all piping in place and 99% hidden and buried in concrete floor or walls. If my "friends" info is correct and to pump the whole system COULD cause a problem I suspect I'll give it a miss. Air testing might give me the answer but if it fails then I'm in trouble again trying to find the leak!!!

Would a small pump adjacent to each appliance pulling the water to one appliance from the open vented CW tank and copper cylinder rather than pushing it round the whole system put the same strain on the pipework?

Thanks for your help thus far.
Rank: Labourer
Progress to next rank:
Posts: 3
Joined: Sat Dec 29, 2007 5:50 pm

Postby bobplum » Mon Dec 31, 2007 6:52 pm

why not speak to the manufacterers and seek there advice
Rank: Foreman
Progress to next rank:
Posts: 364
Joined: Tue Sep 25, 2007 7:35 pm

Postby Big_Dave » Tue Jan 01, 2008 10:37 am

Will do. If I glean anything useful I will post same.

Rank: Labourer
Progress to next rank:
Posts: 3
Joined: Sat Dec 29, 2007 5:50 pm

Postby marrtin » Tue Jan 01, 2008 1:44 pm

One point worth mentioning, is that pumps are designed to push not suck water so fitting them at the appliance end may cause unexpected problems.

I am not sure you should worry too much about the risks of a leak. Don't forget the pipes will only be under pressure when the pump is running, and as you will be drawing water so that alone will restrict how much stress the pipes are under.

It is not written in stone that you WILL have a problem. In fact the odds are heavily on your side even if you were fitting a combi running at more than 4 or 5 bar. Remember the pipe will only fail at a weak spot. It may fail tomorrow anyway.
Rank: Foreman
Progress to next rank:
Posts: 374
Joined: Fri Oct 26, 2007 6:42 pm

Display posts from previous
Sort by
Order by

  • DIY How to Project Guides
  • DIY how to tutorial projects and guides - Did you know we have a DIY Projects section? Well, if no, then we certainly do! Within this area of our site have literally hundreds of how-to guides and tutorials that cover a huge range of home improvement tasks. Each page also comes with pictures and a video to make completing those jobs even easier!

  • Related Topics