[Paul Redden Countryfresh]

I have a Ninja with internal heat exchanger, I have swapped my 135 psi pump for a   
150 high flow shurflo induction pump. My problem is it overheats then cuts out, restarts
when cooler. I wondered if the heat exchanger is causing resistance. works ok with 135psi.

The pump No is PN SF07-030 / intermitent duty / Ser 140423 / 0.65 amp /  2750 rpm/ ccw 5uf/400vlts

any input appreciated, i will try by-passing the exchanger.                                                                                                                                                                                                                                                                 

[Mike Halliday]

if the pump is over heating then perhaps  it is working too hard, have you tried it with an open QC so there is no restriction to the water flow. the pump has to work harder to push the water through a small jet

[John Kelly]

It might be the intermittant duty which is the problem. These are usually designed for taps on boats or caravans where the only switch on and off occasionally.

[Paul Redden Countryfresh]

If i run a open ended hose into the tank it does'nt cut out. Tried by-passing heat exchanger
no change. If I open by-pass to reduce pressure it seems ok.