Think we can safely say that the thermo cartridge on the new mixer is just enough to restrict the flow beyond pump activation. 
Shower pump problem
- Thread starter Gilesda
- Start date
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I'm going to mothball the thermostatic bar for now. I'm busy converting a downstairs room off my utility into a downstairs shower room so I'll keep it for that if I ever get it finished. Hopefully it will work on the ground floor or if I get a combi fitted. I liked that valve when it worked the overhead rainfall thing didn't half chuck the water out.Think we can safely say that the thermo cartridge on the new mixer is just enough to restrict the flow beyond pump activation.
I live in the north east and Argos has one of its few clearance stores near me at a place called Stanley. I was in there on Friday and they had Triton Westbourne bar mixers for £75. I'm wondering if a different thermostatic valve would work in my current system or if I'll have the same problem?
What are the MI min flow rates? That's the key question.
Eight litres a minute according to Triton and .5 bar pressure which is the same pressure needed as my previous thermostatic.
I'm not sure how this works. The pump needs 2 litres a minute but the mixer needs 8. So does that mean I need 8 litres a minute before the pump otherwise the water doesn't move through the mixer to activate the pump?
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Tricky one that. Might be worth a call to Triton but not sure how that can be calculated in advance! Need to know what the restrictive effect is across the valve/through the thermostat cartridge.
Remove the non return valves in the bar mixer, you don't need them with a pump, that will increase the flow rate if that doesn't work you will need a negative head pump.
https://www.showerdoc.com/stuart-turner-monsoon-pump-universal-u2-0-bar-twin-46480
Most non negative head shower pumps need 0.5 bar to activate the flow switches
The head height is measured from the highest point of the system in your case the pipework
in the loft to the base of the cold water tank the minimum height you require is 500mm.
500mm = 0.5 bar
https://www.showerdoc.com/stuart-turner-monsoon-pump-universal-u2-0-bar-twin-46480
Most non negative head shower pumps need 0.5 bar to activate the flow switches
The head height is measured from the highest point of the system in your case the pipework
in the loft to the base of the cold water tank the minimum height you require is 500mm.
500mm = 0.5 bar
Sorry .... Have to disagree, it isn't pressure that activates positive head pumps, it's flow.
and .... erm .... nope ... 500mm height = 0.05bar =====> 5m height = 0.5bar
Sorry .... Have to disagree, it isn't pressure that activates positive head pumps, it's flow.
and .... erm .... nope ... 500mm height = 0.05bar =====> 5m height = 0.5bar
Brain dead today lol
I've got less than 100mm head, the pipes in the loft are just under the tank.
I thought the head to the pump was from the underside of the CWT to the pump itself. The head to the shower is from the pipes in the loft to the CWT which is very low and why I need a pump. It's all a bit confusing. [ :-- )
You could always bodge it by fitting a pneumatic switch in the bathroom ie. an air operated "switch" (for safety) connects to an air line that operates an electrical switch near the pump..and that temporarily shorts the pump flowswitch to get it started.
Just to add a bit of advice as the manufacturer,
This pump requires a minimum natural flow of 2 litres per minute individually on hot or cold to activate the pump, 4 litres per minute combined flow with the shower on a mixed setting. This can usually be achieved where the cold water cistern is located greater than 600mm above the highest point in the system, downstream of the pump, so shower heads or 'up and over' pipework, whichever is higher.
Testing should be as the shower is naturally used ie. where the shower head is used.
If the shower has a minimum operating pressure of 0.5 bar, the cold water tank would need to be sufficient height to achieve this. However, only the shower manufacturer can advise on what flow rate you would expect to see through the shower with the pressure you have.
Personally, I don't think there is anything wrong with the flow switches as you mention it works with the other shower but if you want to test the pump, a washing machine hose or something similar on the outlet of the pump, into a bucket, then turn the inlet isolating valve on to see if the pump activates, try this on both sides of the pump.
If you require any further assistance, please feel free to give our tech team a call on 01915162002 and they can help further.
cheers
This pump requires a minimum natural flow of 2 litres per minute individually on hot or cold to activate the pump, 4 litres per minute combined flow with the shower on a mixed setting. This can usually be achieved where the cold water cistern is located greater than 600mm above the highest point in the system, downstream of the pump, so shower heads or 'up and over' pipework, whichever is higher.
Testing should be as the shower is naturally used ie. where the shower head is used.
If the shower has a minimum operating pressure of 0.5 bar, the cold water tank would need to be sufficient height to achieve this. However, only the shower manufacturer can advise on what flow rate you would expect to see through the shower with the pressure you have.
Personally, I don't think there is anything wrong with the flow switches as you mention it works with the other shower but if you want to test the pump, a washing machine hose or something similar on the outlet of the pump, into a bucket, then turn the inlet isolating valve on to see if the pump activates, try this on both sides of the pump.
If you require any further assistance, please feel free to give our tech team a call on 01915162002 and they can help further.
cheers
I've had another try at getting the thermostatic mixer bar rainfall shower to work and it now works perfectly. I finally did what @steve32 said to do on page 1 and remove the nrvs built into the mixer. Took them out and it works great.
Previously if I changed the temperature or moved between shower head and rainfall the pump paused momentarily. Now it doesn't cut out whatever I do.
So thanks again for all input and advice it was much appreciated. I've learned a lot.
Previously if I changed the temperature or moved between shower head and rainfall the pump paused momentarily. Now it doesn't cut out whatever I do.
So thanks again for all input and advice it was much appreciated. I've learned a lot.
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It wasn't the pump it was a combination of my setup and the mixer having too many restrictions for it all to work properly.
It's good to see a manufacturer have a representative on a message board like this. My CT50 has been in daily use for about 9 years and never given a problem even though I don't have it in an ideal position. It's a decent testimony for the make really. If I get another 2 years out if it I'll be more than happy.
Sunderland is well served for pump manufacturers. We've got Salamander on the riverside and the other side of Wessington way is Grundfos. Is that a coincidence or are the two linked?
Gilesda,
Happy to help and glad you have been pleased with the pump over the years!
And no... not related to Grundfos....
Happy to help and glad you have been pleased with the pump over the years!
And no... not related to Grundfos....
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