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!

 

[SimonG]

Was it a plumber that installed it?

Has the hot feed been taken from the cylinder as close as possible?

Is the pump in the airing cupboard?

Has the 'plumber' provided a tanked cold feed to the shower or tied it into the mains?

Any pictures?

 

[iain85]

Just googled the ct55. It is a single pump impeller so by the sounds of it the hot water is provided of the pump and the cold is from the header tank.
Sounds like the hot water is pushing back on the cold water supply and to overcome this you really need a twin impeller pump to have equal pressure (cold water pumped as well ). Really the plumber should of known this, and at the very least hasn't checked it after he installed it so I would call him back.

 

[SimonG]

If the ct55 is single impeller then my moneys on tanked hot and mains cold.

 

[PlumbingNewb]

Hi

Thanks for the replies. Some answers here:

1. It was a plumber, at least he advertises as such and thats what his invoice says!
2. The pump is situated right next to the hot tank - there is a pipe from the hot tank into the pump, and another pipe out of the pump which disappears below the floor. The cold pipes weren't touched. Assuming that this answers "Has the 'plumber' provided a tanked cold feed to the shower or tied it into the mains?"?

We did speak to him and he suggested he might need to fit some non-return valve(?) but I really dont understand why turning the hot tap stops all the cold water, and vice-versa. This happens from the bath taps as well as the shower (which comes from the same taps), but isnt a problem with the sink taps which are in the same room.

 

[tom609]

as previously a twin impeller pump should be installed what shower make and model

 

[iain85]

Yes, It answers question 2 in the negative.

Basically because the hot water is a higher pressure, it is forcing the cold back down the cold water supply at the point of the 2 mixing. The none return valve will not solve this as it will still not allow the water through.

I suggest a 2nd local opinion.

 

[Plumber live]

Get said plumber back, He's messed up the install. Although probably better to call different plumber . Who knows what there doing.

 

[Billy Bob Bob]

sounds like your plumbers a numpty

 

[PlumbingNewb]

So basically, hot is now too powerful and is stopping cold from pouring in for mixing? I think we'll have to get him back - I can see this being an uphill struggle to get him to do it properly (i.e. swap the single for the double)

 

[Billy Bob Bob]

So basically, hot is now too powerful and is stopping cold from pouring in for mixing? I think we'll have to get him back - I can see this being an uphill struggle to get him to do it properly (i.e. swap the single for the double)

yep he probably wont be able to fix it

 

[tom609]

you could always put another single impeller on the cold. not the way i would do it but hey ho

 

[PlumbingNewb]

you could always put another single impeller on the cold. not the way i would do it but hey ho

Yes thats what I am thinking now. Do you think I would be within my rights to ask him to remove the single impeller pump and replace with a dual? Its really frustrating because we had actually said that we think we needed a dual pump but he would "see what we needed".

 

[tom609]

without knowing what you have its hard to say but in general a gravity fed shower which to me sounds what you have you would need to fit a twin impeller pump though you may need a negative head pump depends on your system have you paid him if its a standard system he should know better you can always contact salamander pumps they will tell you what you need for your system

 

[PlumbingNewb]

Already paid him unfortunately - I might contact Salamander to ask what they think we needed. Not sure what type of system we have (didnt realise there were so many types to be honest!).

I'll speak to the plumber as well and see what he proposes but so far not filled with confidence by him

 

[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?