Showerpump overheating.

[Tachyon]

I replaced a shower pump around a month ago. It was a Salamnder CT50+ Xtra pump and it was pretty much a straight swop for the old one with very minor pipe adjustments. The pump works great, great pressure, always starts etc... does nothing it shouldn't be doing except after around 5 to 6 mins the motor casing is starting to get quite hot.
It doesn't have a direct feed or specific flange fitted as recommend as it's teed off existing plumbing into it's own 15mm pipes then into the anti-vibration hoses on the shower. I've put the shower hose in a bucket and checked for air and there's no air bubbles coming through with the water. The supply without the pump in operation is well above the minimum required for the pump to function so I don't think it's being starved of water and there's never any drop in pressure of the course of it running. It also has a continuous use rating which is why I'm a bit concerned at it getting quite hot, surely it shouldn't do this?
Would it be a plumbing issue or is it possible there's a fault with the pump that's causing it to overheat? I'm not sure whether to see if I can return it for another one but if I thought the plumbing was at fault there wouldn't be much point.

 

[BuffetSlayer]

Have you checked the instructions for maximum operating temperatures of the hot supply?

Most pumps have a max of 50-60 degrees C.

The other thing could be if the pump is labouring due to partial obstruction somewhere. Do you have hard water?

Of course it could be that it is normal for it to work at those temps. I would contact the manufacturer and ask.

 

[Tachyon]

I tried it earlier when there wasn't much hot water in the hot water cylinder and it was the same thing, casing got very hot. I don't think there's an obstruction as when I switch the pump off and run the shower unpowered it still gives a reasonable output compared to the pump min specs. Pump specs state 4l/min minimum whereas when I run the shower unpowered it gives 8l/min. Not really sure about hard water, never really have limescale problems in the kettle etc.. so I'm thinking we don't have hard water issues in our area. Thanks for reply and suggestions, will maybe give Salamander a call tomorrow and see what they say, I just suspect they'll say I need to have direct feeds and the use an appropriate flange etc..