Question on replacement pumps (3rd one in 2 years!)

DesperateDan

Hi folks,

We are getting a new pump in the hot press shortly and I just want to make sure I'm not asking a stupid question because this is going to be costing a lot of money.

It's a long story but this is the 3rd pump in two years, first two were put in by a family friend now-retired plumber that evidently didn't have a clue what he was doing. Pump number 1 was a Salamander (CT85 I think, around €200), green one.

After 1 year the hot side burnt out and I brought it in to replace it and the shop keeper asked me what it was feeding: Mixer bath tap, mixer bathroom sink tap and the hot kitchen tap some metres away. This is a small cottage now so not crazy distances either. He told me straight away we had the wrong pump and needed a twin impeller so we got given a Salamander Crossover (blue this time, around €300).

Now almost a year later here we are after the Crossover fried. A Salamander guy came around and took one look at it and said the pipes going into it were not large enough. Looks like our retired plumber friend used the hose fittings from the original CT85 with a UK size of 15mm which were too small for the Crossover. But also we suspect the pump was never designed to be turned on and off constantly with the kitchen taps in use.

So we've nice new plumber coming around to have a look that really knows what he was talking about. It'll be a brass Grundfos pump of some kind going in, plus some kind of valve on the top of the hot cylinder which apparently should have been in at the start.

Having a look at this page, should I be making sure it's not a "shower booster" pump that's going in? The SCALA2 looks very fancy, maybe I should be making sure that's what he had in mind? The plumbing is old and I know that some new pipe fittings are going in too.

anthonyos

Have you a picture of the old one

DesperateDan

anthonyos wrote: »

Have you a picture of the old one

Sure here it is still in situ in the horrible wee cupboard no-one dares open

corkgsxr

Plastic pumps last pissing time.

If water is too hot or abit of air it runs them.

The brass is much much better. And from the sounds of it he is plumbing it better too

rightjob!

Plastic body pumps are cheaper as they dont last as long,also the hot water is more than likely getting heated to over 65degrees which is also bad news.

You want a brass body pump and also get the hot water temperature checked.

DesperateDan

Grand yeah, the water was always 60-65 so I don't think it was too hot, just overuse and not enough water getting into it, plus air etc. I'm sure all adds up. So if I'm looking at a brass shower pump though for example he comes round with one of these, it's still going to last despite the fact that it'll end up being turned on and off one hundred times a day with the kitchen tap using it as well?

Dtp1979

DesperateDan wrote: »

Grand yeah, the water was always 60-65 so I don't think it was too hot, just overuse and not enough water getting into it, plus air etc. I'm sure all adds up. So if I'm looking at a brass shower pump though for example he comes round with one of these, it's still going to last despite the fact that it'll end up being turned on and off one hundred times a day with the kitchen tap using it as well?

There should be a mixing valve fitted before the pump, with the hot for the mixing valve being fed from a Surrey flange or similar, and the cold for the mixing valve fed from the attic tank directly. The cold to the pump should have its own independent feed too.

DesperateDan

Dtp1979 wrote: »

There should be a mixing valve fitted before the pump, with the hot for the mixing valve being fed from a Surrey flange or similar, and the cold for the mixing valve fed from the attic tank directly. The cold to the pump should have its own independent feed too.

Interesting okay, what does the mixing value do? I am assuming this pump will have the same 2 inlets and 2 outlets so the hot and cold water is separate.

I think Surrey flange is probably what he had in mind. Original plumber has probably never even heard of them

Dtp1979

DesperateDan wrote: »

Interesting okay, what does the mixing value do? I am assuming this pump will have the same 2 inlets and 2 outlets so the hot and cold water is separate.

I think Surrey flange is probably what he had in mind. Original plumber has probably never even heard of them

Mixing valve reduces the water temp going into the pump. 50degrees is more than enough

Rew0505

What happened to a pump? Salamander crossover is well build pump and should last much longer then a year, so installation is issue here, pump should be installed as close as possible to hot water supply (hot cylinder), it should have direct supply for both cold and hot water, hot supply from air free cylinder flange,
If air gets into system from hot water cylinder it would cause pump pulsing on/off every few second and can fried up any pump brass or plastic in no time.