Salamander Negative Pump Pulsing issue

[budedwards]

Recently had a Negative pump fitted that was sourced used to keep costs low. The pump has followed all the tests provided by Salamander support and runs perfectly. However when hooked up to the Thermostatic valve it pulses. 6 seconds on, half second off, 6 seconds on and so on.

If i remove the shower hose from the thermostatic valve this increases the pulse time to around 20 seconds on and half second off.

I have purchased the widest bore shower hose i could find 12mm but this has made little difference.

I am not convinced i needed a negative pump..

anyone ever come across this issue?

The CWT is in the loft and the shower is on the floor below the other side of the hot water tank.

 

[ShaunCorbs]

Where is the pump fitted ?

 

[budedwards]

Where is the pump fitted ?

Hi Shaun,

The pump is fitted in the cupboard next to the Hot Water Cylinder.

 

[ShaunCorbs]

Did you check the vessel charge on top when empty ?

Also you haven’t plumbed it in to spec eg s flange ?

 

[budedwards]

Did you check the vessel charge on top when empty ?

Also you haven’t plumbed it in to spec eg s flange ?

I did check and top up the vessel post install following Salamander how to video mate

The plumber installed it mate not me, would you mind elaborating what you mean by flange?

 

[ShaunCorbs]

Should be like this as the way you have it can lead to air coming in via the vent and stopping the pump

 

[budedwards]

Should be like this as the way you have it can lead to air coming in via the vent and stopping the pump

View attachment 76823

wow ok, thanks for that.

I'll speak to the plumber and see if he can rectify

 

[SimonG]

Problems are it's a salamander, it's been installed by a half wit, it looks like it tees off of the cylinder cold feed and hot same as above.

 

[budedwards]

Problems are it's a salamander, it's been installed by a half wit, it looks like it tees off of the cylinder cold feed and hot same as above.

so which problem is causing the pulsing?

Here is the pipework consideration.

I'll happily get in a different plumber if the issue is the setup

Also i was trying to determine if it was a negative pump i needed all along but no-one has mentioned that as a potential issue.

 

[ShaunCorbs]

Plumber is the issue and negative head wouldn’t effect / cause the pulsing