Headhunter Mach5 pressure problems

Breaker on?
Power light on the pump on?
Fault/error light flashing?
Have you turned the breaker off and on?


Most problem with these pumps are caused by a leak on the suction side. Once you have it running, open 2 or 3 faucets then run the pump till water flows then turn off the breaker till it stops. Repeat 5 or 6 times then turn the faucets off. There is a video on the website explaining this purging method.

Is there a pressure gauge? What pressure is it cutting out?
I fear it is stopping with an error and you think it is just an off cycle.
This bug has bit me once.
No increasing load on the motor in a certain time, Off it goes till power cycled.
Later pumps tried once or twice more.

The pump uses current drawn, current ramp & time to determine a load on the motor shaft. I do not recall a cut off switch, just on.

Air in the low side is the usual cause. The turbine/compressor wheels inside that pump is impressive but does not deal with air at all.
HH uses O rings at each end adaptors. Food grade grease may only is used here.
Not tapered pipe threads, teflon tape will not work.

HH support is great if an email or call is needed. They will need the model & serial number to answer any questions.

So it has power and it runs. Good. Try the purging I mentioned or look up the detailed video on their website.

the Mach 5 is probably the best fresh water pump but as I said earlier it is sensitive to suction leak. I had the issue on an 84 Lazzara where the pump would occasionally need to be reset. One of these annoying thing which aren’t broke enough to really spend time on. Next and current boat, a 110 lazzara and the pumps are running flawlessly. Knock on wood… I probably just jinxed myself . We have two of them, using one at a time with a selector switch and valves.

My cheap pressure gauge shows about 70#s when it stops. You can sure feel that 70#s when it runs.
Our DCv pump (water saver) builds up about 35.
Time to call HH for service.

19 year old pump has a pressure switch.
And it failed. Frak..
I would luv to tear into that old pump and learn more about their old pressure switches.
At the least, I'll have another pig sized target..

Sent a PM

They used to give 50% off on a new pump when out of warranty. You only had to return the sticker with serial number.

Just had one of the two Mach 5 fail last week end. Thankfully the boat has two pumps so I just had to flip a switch and valves.

new Mach 5s have doubled in price since I last bought one 5 years ago to $1900. Painful but that’s what happens with high inflation. And they no longer have the 50% off when you turn in your out of warranty pump.

I decided to do a post mortem on the dead pump and it turns out the capacitor was blown. I ordered a new one from a place called Cafe Parts! Yes these Ducati Electric caps are used in coffee machines. Hopefully that will fix it and we ll have a spare

As noted above, Badcoupe34 did send me his bad HH5 (Thank You).
For $2.oo It was fixed, Bad lil micro (Cherry) pressure switch.
I spent more time repairing a broke screw in the case body over the flow sensor, than fixing the pressure switch.

So, no pig sized target for my SKS & Saiga.

Then. I installed it in a friends Hatt. That kid has gone thru a few different well pumps, He is finally happy.
If/When it fails, and I can't fix it, he will purchase a new HH and I'll have my pig target back.

Thru the years of tinkering, I have found these pump motors and staged impellers to be near bomb proof.
Flow sensor and that lil board are next common (rare) failures.
A bad cap is a new one on me. But, ship happens.