Immersion heater and Salamander CT55XTRA pump

[dazzler9000]

Hoping somebody can help. In my rental flat, the hot water is fed from an immersion heater but the flow rate was abysmal.

I had a plumber install a Salamander CT55XTRA pump several years ago to provide more pressure. It's never been great and has worked intermittently. At times, when it did work, it seemed to switch on and off quickly during its operation. A few weeks ago, it stopped altogether. I tapped it with a hammer and it worked for a couple of weeks. Now, it's stopped again.

I think there are some filters in line with the feed pipes, so I will check that. If not, any ideas?

 

[Wayners]

Service Engineer Visit | Salamander Pumps

If you have already had a free of charge replacement product under warranty and/or you would like one of our engineers to come onsite and assess the installation, then this can be easily arranged.

www.salamanderpumps.co.uk

Maybe get the company to come out and look.
Is it still under warranty

 

[Exedon]

To be truthful salamander aren't the best some clear pictures of installation and a sketch of pipework layout with hight from bottom of tank to highest outlet would be useful.

 

[dazzler9000]

Service Engineer Visit | Salamander Pumps

If you have already had a free of charge replacement product under warranty and/or you would like one of our engineers to come onsite and assess the installation, then this can be easily arranged.

www.salamanderpumps.co.uk

Maybe get the company to come out and look.
Is it still under warranty

I'm sure it's out of warranty now and I'm not even sure who fitted it now, it's something my brother organised.

 

[dazzler9000]

To be truthful salamander aren't the best some clear pictures of installation and a sketch of pipework layout with hight from bottom of tank to highest outlet would be useful.

Oh really, no surprise. Next time I'm there, I will take some pics. I did wonder if it was a water flow problem. I have no idea how these things work. Would the pump pull from the tank or just pump what water is already sat at the inlet that's been fed by gravity?

 

[dazzler9000]

I had a quick look today when I was there. Posted below are a couple of pics.

It looks like there is a feed from the top of the water tank into the pump and then the output from the pump goes into the copper pipes which feed the hot taps around the flat.

I couldn't actually find the stop cock today, so was limited to what I could do, but have located it now, so will return one day and take a look.

If the pump is dead, can anyone recommend a better replacement? Also, is this configuration a suitable solution? I don't think it's ever worked brilliantly, even when it worked. I always suspected that the pump could empty quicker than the pump could be gravity fed from the tank?

 

[stem]

The CT Xtra 55 model is one of the smaller capacity models so 15mm pipe is the specified size to provide the water it needs. However, you would have a problem if the cold water storage tank feeding the hot water cylinder is too low, (it should be 600mm above any shower head). Or, it's actually running out of water because it is either too small, or the cold water filling it from the mains supply isn't sufficient to keep up with the pump. If it does run out of water, the flow switch that controls the pump motor shouldn't operate and the pump will stop. The same if the filter is blocked and is restricting the flow.

These pumps are designed for operation with relatively low temperature hot water, somewhere around 60-65 degrees C, and can be damaged by temperatures in excess of that. I find that hot water cylinders heated by electric immersion heaters can often have much higher temperatures, in which case the pump should be fitted with a thermostatic mixing valve which will blend the hot water with cold to keep the water temperature going through the pump within its operating temperature range. Not a problem of course if your hot water isn't actually errm....too hot.

Also, air bubbles collect at the top of hot water cylinders when the water is heated and it would be usual to fit a special flange [eg Surrey Flange or Warix Flange] to stop the air being drawn into the pump. From your description this doesn't seem to be the case. Although I believe the pump motor would still run, but too much air could interfere with the water flow.

the output from the pump goes into the copper pipes which feed the hot taps around the flat.

I understand that the CT Xtra 55 model is designed for use with a single shower, and larger models are used when the pump is supplying the hot water taps as well, so perhaps it's been operating beyond its design spec (especially if it's filing a bath) which I'm guessing might contribute to an early demise.

 

[dazzler9000]

Thanks Stem, some great advice there.

Yes, I did wonder if the pump was running out of water but I'll be honest, I don't know how it works. I assumed the pump spinning would actually 'pull' the water from the cylinder, hence not relying on the gravity feed, but going by your description, it appears it might just be gravity.

I don't actually know if there is a storage tank, all I can see is a single cylinder, either way, it's not higher than the shower head. Guessing I need a negative head pump?

I'm in two minds about what to do. I believe the proper fix is to get a pressurised cylinder installed but it's a rental flat that makes very little money. I may just replace like for like and see if it works for another 3 years until I sell it.

Would anyone recommend Grundfos over Salamander?