pump distance from tank

[muggles]

Sorry - I'm not being very clear.
The hot water tank is in the back bedroom, this is next to the family bathroom. The run is ~5.5M from the tank to the location of pump which is going under the bath. The pump will serve, bath, 2 showers and hot water taps. + hot water for downstair loo and kitchen The original set-up was a dedicated shower pump (cheap variable speed b&Q 2 bar one) and a dedicated pump for the bath (wickes brass 3 bar) and ensuite bathroom. Since we are having the bathrooms redone. The "plan" was a single high quality pump next to the tank.

diagram : https://c2.staticflickr.com/8/7434/27777430691_ea9e88e00c_z.jpg

So I'm assuming there aren't any pumps designed to be so far away from the tank?

Ah, you're talking about your cylinder. I thought you were taking about your loft tank. It's all much clearer now.

No, there aren't any standalone pumps I can think of that will do that kind of distance - it needs to go in the airing cupboard. If you're pumping the whole house you'll need a higher spec pump too

 

[motorbiking]

starting to think mains pressure h̶o̶t̶ ̶w̶a̶t̶e̶r̶ ̶t̶a̶n̶k̶ Cylinder might have been easier - though the quote for that was £1,500.

Given that there is now no option to change the location, will increasing the capacity of the pump (e.g. a 4 bar Monsoon) make matters worse?

From what I can make out the issue with the length of the run is wear on the pump and the potential for it to leek as well as its ability to deliver the demand

 

[muggles]

The issue with the distance is the potential for air to be drawn in, increased risk of cavitation, and asking the pump to do something it wasn't designed to do. If it breaks down in the warranty period and hasn't been installed in accordance with the manufacturer's instructions, they'll take one look at it and declare your warranty to be invalid

You should be looking at the Monsoon Extra range for whole house applications such as yours

 

[motorbiking]

how about connecting the cold from the cystern tank direct to main, bypassing it for cold feed and hot only pump in the cylinder cupboard. my mains flow isn't amazing but it's probably up to the job.

I'd have to flow test it I reckon and then try to match it with the appropriate pump.

 

[muggles]

You can do, but you'll need to put check valves on every cold tap and shower supply to make sure the pump doesn't push hot into the mains. Better to pump both if possible

 

[motorbiking]

do the monsoon extra's come with twin pumps?

 

[Agile]

As I understand your diagram, there is 3.6 m on the cold feed and 2.1 m on the cold.

My expectation of the pump requirement is for a minimum of 4 m of pipe on each of the cold and hot inputs.

Tony

 

[motorbiking]

I looked at the pic and I can see how you can see that.. but no its my bad drawing. Bedroom is approx 12ft wide and bathroom 7ft so 19 feet. add a bit for the wall between and take off a bit for bath width / 2 and and cylinder / 2 (centre point) and I conclude approx 18 feet ~ 5.5M

I now have a dilemma - as Plumber is saying you can't get a pump that does a run of 5m - salamander say their regeneration pumps do up to 5m, but everyone here says salamander are poo (which is backed up by too many reviews), so I'm about to order a Stuart Turner 46410 (3 bar twin, + and - ) I can't find a bad review about Stuart Turner where as I struggle to find a good review about Salamander.

I've concluded based on the advice here - better to exceed the warranty input distance with a quality pump than go for one with a poor reputation.

its bloody annoying given the builder agreed he'd locate pump in airing cupboard and plumber said it couldn't be done. There is nothing odd about my set-up. Given I've had new ceilings and everything downstairs they could have easily installed new pipework for the job.

A crazy thought - would it be worth me stepping up the run of pipe from the cylinder to the bathroom that goes through the bedroom to say 28mm and then back to 22mm..?

so cylinder out is 22mm -> 28mm for 4M then back to 22mm?

 

[dilalio]

That's why you shouldn't be consulting a builder regarding plumbing matters I'm afraid!
They are known for their favourite phrase: "Yeah! That'll work, no problem!"

 

[motorbiking]

I'm leaning towards the - we can't be bothered to do the extra piping rather than it wont work. IMO all he had to do is run a cold feed 5M along the loft and down in the airing cupboard and then connect the pump in at the base of the tank. Alternatively - I'd have gone two separate single end pumps, or Hot pump mains cold. I've had builders before and have always been very pleased with the work, this builder seems to be using sub who aren't very good. I can only conclude he's making a big margin and paying them peanuts.

 

[Agile]

The supply of cold is not a problem because the flow rate will normally be low. Its the hot which is a potential problem.

Even so the problem will be more pronounced with higher flows.

Larger pipework diameter is likely to help but the makers have to decide to say one thing and they do that based on 22 mm pipework which is most common.

Have they considered all the options?

Suppose the cylinder was raised by about 600 mm? Then the pump could go underneath?

Good plumbers don't want to work for builders!

Tony

 

[motorbiking]

Unfortunately plumber told the mrs what the problem was and she had no clue what she was being told and said "ok", tilers have completed their work, so unless I cut the cold from the cistern tank, run it to the airing cupboard to pump and then back up to loft and back to where it was - its now too late to change.

either that or I cut a hole in the new ceiling which I have just painted. I do have to consider that this (similar below) pump managed in this situation for 15 years: I don't know what kind of pump this is:

 

[Agile]

That looks like a good pump!

Most seem plastic now!

And why can the cylinder not be raised?

Tony

 

[motorbiking]

There is plenty of room for the pump in the airing cupboard, and there would be no problem raising the cylnder - does this improve the input challenge or did you mean raise it so the pumb would go underneath?

 

[Agile]

I dont understand what your problem is.

You seemed to be saying the pump cannot go by cylinder. I thought that was because it will not fit.

Now you are saying that it can fit there.

So what is your problem about fitting it there with a short supply pipe length?

Tony