JABSCO PARMAX 2.9 Fresh water pump

[Hayling]

My fresh water pump is pressure controlled, open a tap and it kicks in,
until now. It no longer kicks in, I have to reach behind a cushion to knock it
to stir it into action, then it runs until the tap is turned off and I have to repeat next time.

Anything I can do apart from reaching for chequebook?

 

[Aeolus]

There's an adjustable screw under the blue cover at the front of the pump. Try turning that and see if it fixes the problem.

 

[ex-Gladys]

The Parmax 2.9 when I bought it to replace the old Rule FW pump, it was cheap as chips compared with Rule repair kit. I also tried to work out a solution for manual emergency FW pumping, but couldn't for any reasonable cost. My pragmatic approach is to carry a spare Jabsco pump... A quick Google reveals they're available for under £60

 

[jwilson]

The pressure switch is removable and replaceable from the makers spares list.

 

[Hayling]

Very helpful, thank you,
I will have a ferkle!

 

[Richard10002]

There's an adjustable screw under the blue cover at the front of the pump. Try turning that and see if it fixes the problem.

What is the screw designed to do?

 

[sjdtuk]

I find it best to fit an external pressure switch.

 

[Momac]

What is the screw designed to do?

It adjusts the pressure at which the pump starts/stops.

I took a similar Flojet quad pump apart - fitted new O ring , removed some limescale. The inlet filter was limescaled too - easily cleaned. The o rings on the inlet and outlet needed replacing.
One of the electrical spade connectors was so corroded it crumbled. A new connector was fitted. This was a significant fault and possibly the fault in the case described here.
Could only see this fault with the end cap off and this required the pump to be removed in my case - which was not particularly difficult.
I had the pump on and off a few times but next time could do it blindfold!
Everyone said I would need a new pump.

 

[Richard10002]

It adjusts the pressure at which the pump starts/stops.

I took a similar Flojet quad pump apart - fitted new O ring , removed some limescale. The inlet filter was limescaled too - easily cleaned. The o rings on the inlet and outlet needed replacing.
One of the electrical spade connectors was so corroded it crumbled. A new connector was fitted. This was a significant fault and possibly the fault in the case described here.
Could only see this fault with the end cap off and this required the pump to be removed in my case - which was not particularly difficult.
I had the pump on and off a few times but next time could do it blindfold!
Everyone said I would need a new pump.

I'm looking to increase the pressure at which the pump cuts in - which way would I turn the screw, and would this also increase the pressure at which it cuts out?

Found this on servicing:

http://www.laltraranda.it/sites/default/files/images/Service PAR-MAX 31xxx and Flojet Quad.pdf

and this is an extract towards the end of the page - presumably this is the screw under discussion?

"Note: The pre-mounted screw on the face of the switch
housing is the pressure adjustment screw. This is a factory
pre-set switch, DO NOT ADJUST. Adjustment other
than the one made by the factory voids the warranty."

 

[Richard10002]

I find it best to fit an external pressure switch.

In the event that the screw in the built in pressure switch doesn't do the trick, how does one go about "fitting and external pressure switch":

Sounds good, except that it's easy for you to say, and gobbledegook to me

1) What kind of external pressure switch? Can you suggest a specific one that would do the job, (and provide a link )

2) Are these pressure switches push fit onto Speedfit or Hep2o pipe, or would I need to sort out some joints/couplings?

Hope that makes sense, and hope it helps the OP as well as me

 

[Momac]

Turning the screw clockwise it cuts out sooner.

 

[Richard10002]

Turning the screw clockwise it cuts out sooner.

Thanks for the help. Done it now and found that clockwise increased the pressure at which it cuts in and cuts out. I now have a much better flow of hot water from the Rinnai gas water heater and, as a side effect, a much more powerful flushing toilet

 

[sor1n3l]

This is great info! A quick search on google revealed this https://www.foxschandlery.com/jabsco-par-max-2-9-pressure-pump-31395-0292-12v . It looks like that at the moment they are the cheapest out there.

 

[catlotion]

Thanks for the help. Done it now and found that clockwise increased the pressure at which it cuts in and cuts out. I now have a much better flow of hot water from the Rinnai gas water heater and, as a side effect, a much more powerful flushing toilet

Old thread I know but this was a handy tip as my pump was cycling noisily when taps were closed. I thought it was the pressure relief on the calorifier misbehaving but I tweaked the pump switch screw (anti-clockwise to reduce pressure) and it fixed the problem.

 

[Elessar]

My fresh water pump is pressure controlled, open a tap and it kicks in,
until now. It no longer kicks in, I have to reach behind a cushion to knock it
to stir it into action, then it runs until the tap is turned off and I have to repeat next time.

Anything I can do apart from reaching for chequebook?

Take the pressure switch off and take it apart. There is a £2 micro switch in there. Replace that. Worked for me I hope it does for you.