Shower pump cutting out

[georgedasave]

Hi

Hoping someone here can help me out, here's the problem

We have a mixer shower fed by cold mains pressure water ( no cold tank ) and the hot water was fed from a shower pump (Bristan Single Impeller Pump). Hot water tank has a cold water header tank and two immersion heaters (no gas in property).

It was working fine until the pump packed up so I changed it with a Salamander CT55, now when you turn the shower to full hot it works fine but has you reduce the temperature to allow more cold through the pump cuts off only allowing cold water through, so it can only be boiling hot or freezing cold.

Would anyone have any suggestions on how to cure this problem?

Many thanks in advance

 

[seco services]

Sounds like when your lowering the temp the flow rate is dropping below the pumps recommended flow rate to operate the flow switch.

What model was the bristan pump ?

 

[georgedasave]

thanks for the quick reply, the pump I removed was this one

http://www.homebase.co.uk/webapp/wc...y?langId=110&storeId=10151&partNumber=1607660

 

[warmadmax]

you may be better off taking a cold feed from the header tank for the shower and a twin impeller shower pump for it.

p.s. bristan pump says the following :
Usage: Ideal for boosting a single water supply from a shower mixer or shower head.[/u]

 

[georgedasave]

Thanks for the reply, if that's my only option then I think that instead of having to plumb in new pipes to the shower it may be just as well to fit an electric shower and remove the pump all together

Thanks again

 

[seco services]

I take your cylinder is a combination cylinder.
Is it on the same floor as the shower or floor above ?

Give us some pics or diagram of layout.

 

[georgedasave]

It's a combination cylinder, the cold water header tank is built into the hot water tank. It's a single storey flat.

All I know is the mains comes in and goes to basin, bath, shower, toilet, kitchen sink, washing machine and hot water cylinder header tank, I'm not sure in what order or how, and then the hot water goes to the pump and feeds everything, again not sure how or in what order.

All pipes are under the floor boards

Hope this helps

 

[seco services]

So your shower heads higher than the cold water storage on the combination cylinder ?

 

[warmadmax]

It's a combination cylinder, the cold water header tank is built into the hot water tank. It's a single storey flat.

All I know is the mains comes in and goes to basin, bath, shower, toilet, kitchen sink, washing machine and hot water cylinder header tank, I'm not sure in what order or how, and then the hot water goes to the pump and feeds everything, again not sure how or in what order.

All pipes are under the floor boards

Hope this helps

ok that makes a lot of difference, are you sure all the hot water is pumped?

as Seco is asking, is the shower head level or above the top of the cold water tank?[/u]

 

[georgedasave]

I would say they are roughly the same height. I can't understand why it worked fine with the first pump. And yes all hot water is pumped. I tried bypassing the pump and the water just trickled out. I think my only other option is to fit an electric shower and do away with the pump

 

[warmadmax]

you could try a negative head pump before you subject yourself to an electric shower



http://www.salamanderpumps.co.uk/Default.aspx?PageID=29

 

[georgedasave]

It's in a flat we rent out so really looking for the cheapest option

Would a thermostatic mixer work with the pump I have? Don't really want to pay out for a negative head pump.

Is there a way of making my current pump stay on longer?

Thanks for all the replies so far

 

[seco services]

Would a thermostatic mixer work with the pump I have? Don't really want to pay out for a negative head pump.

Not really cause your shower is in a neg head situation.

Is there a way of making my current pump stay on longer?

Only by converting to neg head but thats not cheap either.