Salamander CT50

[redeyesuk]

Hi All,

Where I live, we've never had decent hot water pressure (so shower from mixer taps is unusable), which I've just put up with since moving in. However, I took off the bath panel yesterday and found a Salamander CT50 pump sat under the bath, which was a surprise!

I'm not sure if this is correct (plumbing isn't a strong point of mine), but the pump is connected directly between the hot water supply (from the tank) and the bath tap. The cold water is not connected, and that end is blanked off.
The wiring is a nightmare and will take some figuring out (it certainly wasn't connected to a live supply), but for testing purposes I connected a mains plug to it and plugged it in to see what happened.
All I got was a slight noise when I turned on the tap and a slight burning smell (which is probably fair enough, it hasn't been used in at least a year), and no difference at all in pressure. The pump body (which I assumed contained the motor) also got very hot - I only had it running for a few seconds.

So, is this unit dead? Or am I missing something? Or is it just badly fitted (given the state of the plumbing here, I wouldn't be surprised)? This is something I've just discovered, so I'm not at all sure what to expect from it....

TIA

Garry

 

[gas4you]

First impressions from your post is that it is dead.

If it is only plumbed into the HW do we assume the cold is mains pressure?

If not and the cold is off the cold storage tank in the loft as well, both the hot and cold should be connected to a 'twin' pump to give a balanced supply.

 

[Richard C]

It sounds as though the pump may be seized which isn’t surprising really if it’s been sitting there for any length of time. Weather or not it can be freed off is something you that needs checking & best done by removing the pump & dismantling the ends for inspection; don’t run it again until you check it because if it’s seized you’ll fry the motor in a very short time, if it isn’t fried already!

The CT50 is a twin outlet pump & you say one end is "blanked off", what exactly has been blanked off? Are you sure it’s not a single outlet CT55 pump? These pumps only require line, neutral & earth to allow them to run & many are just plugged into a normal 13A socket outlet; they operate using a pressure sensing switch which turns the motor supply on & off by sensing a drop in pressure when the tap is turned on. If one end of the pump hasn’t been connected to a water supply & the control unit hasn’t been modified, it will run continuously which may be why the installation was abandoned; I can’t see how it would operate correctly otherwise. Running one end of a twin outlet pump dry will also damage the impeller & that’s another possibility as to what may have happened. I’m not sure if the pump control unit can be easily modified to allow single outlet operation & the impeller completely removed but if it’s still serviceable, a separate gravity fed cold water supply from the loft tank may be needed. Either that of replace it with a single outlet pump.

Be aware that any new electrical work in a bathroom must be undertakes by a Part P certified spark or notified, inspected & tested which may be an unrealistic option in your case. Also, for your own safety, I would advise you get any existing wiring under there checked out as correctly installed & safe before you attempt to re-commission the pump as current regulations require various conditions to be met.

This manual may help you to understand a little more about what’s going on;
http://www.salamanderpumps.co.uk/Download/brochure.pdf

 

[redeyesuk]

Thanks for the replies!

It's definately a CT50, that's what's on the label, and an image search confirms it.

When I say 'blanked off', that's probably a bit misleading, what I meant was one end of the pump has never been connected and still has the red caps on the connectors (see here if you're not sure what I mean).

From what you're both saying, it's not surprising it doesn't work! Still, I was considering having a power shower fitted, so if this is a cheaper and easier option I might get a plumber in and have the pump replaced for a more suitable unit.

So considering what's installed already (the cold water is from a tank in the loft, and pressure is fine, whereas the HW tank is on the ground floor and has fairly pathetic pressure), would I just be able to have a single outlet (say a CT55) pump fitted directly in place of the CT50?

Like I say, plumbing isn't really my forte!

 

[gas4you]

I would recommend a twin impellor pump and a seperate cold feed from the storage tank and seperate hot feed from the HW cylinder for any pumped application.

 

[Richard C]

I agree with gas4you, a twin supply pump is always the best bet. It also avoids any chance of unequal pressure & if the pump turns out to be serviceable you can probably re-use it & save around 100 quid!

Remember that although a plumber will almost certainly be able to sort out the plumbing & install the pump, he won’t necessarily be qualified to undertake the electrical work. Make sure whoever you use is Part P certified & supplies you with the necessary minor works compliance & test certificate on completion or it won’t comply with Building Regulations.

 

[redeyesuk]

Thanks again.

I pulled the pump out last night, stripped it down and cleaned it up - as predicted, it was seized. I managed to free it up and reconnected it, it now works!

The problem is, whoever installed it disconnected the wiring to one end and removed the impeller, effectively making it a single pump unit (I'm sure there was a reason, but...). All very well, but what happens is once I turn on the cold tap, it overwhelms the HW supply (even with the pump running) which has the effect of switching off the pump (it senses there is no water flow), so all I get is cold water. So it looks like I'll have to get another pump sorted out and connected up to the CW tank after all!

 

[gas4you]

Are you sure the cold to the bath is off the tank and not mains pressure?

Would explain why only the hot is pumped.

 

[Richard C]

I pulled the pump out last night, stripped it down and cleaned it up - as predicted, it was seized. I managed to free it up and reconnected it, it now works!

Part result then!

The problem is, whoever installed it disconnected the wiring to one end and removed the impeller, effectively making it a single pump unit (I'm sure there was a reason, but...).

Reason is as I said previously; you can’t run one impeller dry or it’ll self destruct & the pressure switch has to be disconnected from the “dry” end or the pump will run continuously. Makes you wonder why a twin pump was used in the first place but I suspect whoever bought it didn’t really understand what they were doing & then discovered the cold was mains pressure.

All very well, but what happens is once I turn on the cold tap, it overwhelms the HW supply (even with the pump running) which has the effect of switching off the pump (it senses there is no water flow), so all I get is cold water. So it looks like I'll have to get another pump sorted out and connected up to the CW tank after all!

I think there you have your answer; most mixer taps don’t work very well & the slightest pressure imbalance will cause problems & if the cold is mains pressure as gas4you suggests, this will cause a severe pressure imbalance which will overwhelm conventional mixer taps. You could try fitting a service valve in the cold feed & restricting the flow to the tap but it’s always hit & miss. You really need a proper mixer valve, preferably thermostatic, but even these will struggle if the pressure difference is too great.

A pumped system works best when both the cold feed & hot water storage cylinder are supplied from a common gravity fed cold water tank, this always ensures an equal pressure head on both hot & cold supply. But, again, standard mixer taps are always going to be hit & miss & you really need a proper mixer valve to take full advantage. It’s worth doing properly as once you’ve experienced a decent pumped shower, you’ll wonder why you didn’t have one before!