Pump Query and a horrible feeling

[PlumbingNewb]

Hi

Our mixer shower has always run slowly with very low pressure (taps seem fine). We asked around and one electrician suggested a dual pump but also told us that this was really work for a plumber. So, we contacted a plumber, told him what the electrian had said and he came out to fit the pump. Its a Salamander CT55 (unsure if more information is needed than that) and it is hooked to our hot water immersion heater (we don't have gas).

Couple of issues:

1. Its extremely noisy - anyone got tips for reducing this? It's acually waking people up in the house!
2. Using the shower, if I turn on the hot water and then the cold, it runs red hot (like the cold tap isnt even on). This is the case even if I turn the hot tap on just a small amount. If I turn on the cold tap first then the hot tap, no hot water fill flow at all and the pump doesnt engage (trust me, I would hear it!)
3. After a short while of running both taps together (hot on first then cold), turning the hot tap off means that I get some warm water - assuming this is hot water that had run backwards up the cold pipe?

My real questions are:
1. Should we have had this single pump fitted or was there a better solution?
2. What on earth is going on with what now appears to be mutually exclusive shower taps? Sink taps will run happily with hot and cold together mixing to make warm, but the bath taps will not (its one or the other).
3. How can we fix it.

Any help VERY much appreciated because at the moment this was £230 down the toilet, so to speak!

 

[Howsie]

What he's done is against the water regulations, get him back to put it right.

 

[PlumbingNewb]

Just a little update:

1. We found that the main shower is, for some reason, gravity fed whilst everything else in the house is mains fed. No idea why. This is the shower that was having most problems (i.e. it was either hot or cold but not both)
2. The other show in the en suite room is, for some reason, cause the pump to pulsate. This one is mains cold though and we have no idea why its pulsating - even when I turn it as cold as possible (its a single dial and not two taps) it still seems to pulse the hot. It has always done this apart from on one occasion when it seemed to behave itself - it might be a coincidence but we didnt have much hot water in the tank at the time, it just ran warm.

Plumber coming out to take a look soon anyway to discuss "options"

 

[SJB6]

You say the hot comes out from the tank and the cold wasn't touched, you also say the hot is a higher pressure than the cold so without seeing exactly whats what it's hard to say. I would of initionally said like someone else that the cold was from the mains and the hot from the cylinder but again without a (decent) plumber seeing for themselves it's hard to say.

These things should have a seperate cold feed from hot water header tank to pump (tank connector outlet same hight as cylinder cold fill to maintain equal pressure) The hot water to pump should come of the cylinder (either a new two port flange in top of cylinder or pump feed comes off after feed to rest of house so not to starve other outlets of hot water). A twin impeller is better for reasons already stated by others.

You should get another opinion (this so called plumber doesn't have a clue). What ever it costs to put right the origional plumber should pay.

 

[europhil]

Did he fit a surrey flange? It dosn't sound like it, This will be the reason for the pulsing and noise.
Are you far from Blackpool? I'm having a full day on pumps tomorrow. So i'll have a couple of spare pumps with me.

 

[jase158]

check valve may help a little but will not balance hot and cold and may be your way of getting him back, tell him you want this and then if this doesnt work ask him what he is going to do about it now.

he should of checked the mains pressure and got a pump to match if off the mains, but really a twin impeller is the best option.

what cylinder have you got?