shurflo pump replaced and now shuddering the boiler

[purple8]

I swapped my leaking shurflo 2901-0212 water pump yesterday for a trailking 2095-204-412...

should be a straight swap. Same 20psi and lpm etc...

the changeover was pretty easy, just one for one, same connections and fittings etc... After turning it back on, it self primed and everything was fine for a while, shower worked better than ever and had a good pressure from all hot and cold taps and no problems.

now tho is very different. Turn on the tap, pressure fine, pump kicks in, but on ending its cycle it seems to send a shudder through the pipes and rattles the boiler. The boiler is probably the highest point in the system, bar the shower head. I have an accumulator on the system by the pump? Should I pump this? Or remove air from it? I feel it is a pressure problem or air in the system after the change. Any ideas of things to do or check would be great. Thanks

[rusty69]

Did you have a seperate external pressure switch in the circuit as per your previous pics? If so,is this still in circuit (if it was a pressure switch), and what are the pressures set to?

[WotEver]

Sounds like Water hammer. I’ll leave someone else to describe how best to address that. 

[Tony Brooks]

That sounds like water hammer that occurs when a supply is suddenly shut off creating a pressure pulse that bounces back and forth along the pipes. 

It is certainly worth checking the pressure in that accumulator to ensure there is some.

If the boat has a calorifier it would be worth inspecting the PRV in case the new pump is jumping it open a sit shuts off.

I think there are fittings to minimise water hammer but I leave that to the plumbers.

 

SNAP

Edited April 12, 2018 by Tony Brooks

[purple8]

pictures show the set up. There is a external switch but its never been connected. The diall is on the system though but not connected electrically.

[Boater Sam]

Its a Mexican pump. so its dancing.

[purple8]

I drained the system again of all water.

then upon reconnecting and powering on the pump I seem to have lost the hammer.

smooth operation resumes

[WotEver]

14 minutes ago, purple8 said:

I drained the system again of all water.

then upon reconnecting and powering on the pump I seem to have lost the hammer.

smooth operation resumes

Perhaps you had air in it somewhere.

Or perhaps you have air in it now...

As long as it works