Is my flow switch bad?

[Matthew Norman]

I recently got a newer Landa machine and the unit my have froze a few times so I had a local shop check it over and diagnose it. They said it needed a new thermostat, pressure switch / flow switch (not sure the difference; it is about 4 inches high, black and has a metal probe that goes in it and sits on top of the unloader) and erupter disc off the outlet of coil.

I Installed all three items myself.

The first day using it the 20hp Honda motor ran very poorly after troubleshooting it found it had a hole in the fuel filter. Replaced the fuel filter and used a trigger less gun/wand and worked great for 3 hours solid.

Today using it with the a trigger gun the erupter disc off the outlet of the Landa eruptured. Put a new one on eruptured immediately.

I just installed a brand new unloader and new erupter disc.

I tried running the machine it was at 2200 psi because I didn't set the unloader yet and noticed the burner stays on. Do you think I have a faulty flow Switch (I replaced it two weeks ago - although it was out in the cold with air blown through the lines?? It was late so I didn't adjust the flow switch to correct psi, could the psi being off be why?

Thanks for the help.

 

[Matthew Norman]

Meant to say unloader to correct psi.

 

[Guy Blackmon]

Matt, did you check psi at skid or end of hose? Did the burst disc let go when it went into by-pass? Landa pressure relief valves (Burst Disc) are not re-setable, get one that is re-setable and can be adjusted.

Sounds like a psi spike caused by the unloader. I'm no expert but had simular prob with my Landa.

 

[Sirocco Jerry]

I like ADDing a Pressure relief to the rupture-disk option..
set the relief at just below the rupture-disk rating, and it won't blow, unless the heater melts it..
This way you have the perfect combination to insure that hearter coil last a LONG time.

Are there any leaks in the high-pressure side of the system ??
..allowing unloader to keep fluctuating the flow-switch, when the trigger-gun is off ??

Does "flow" actuate the heater on and off ..at all?

Give me a call if you need me.

 

[Matthew Norman]

Took the flow switch off and flipped it up and down and the magnet inside loosened up and it's working good as new. I never knew a brand new flow switch could get caught up like this.

 

[Sirocco Jerry]

Took the flow switch off and flipped it up and down and the magnet inside loosened up and it's working good as new.
I never knew a brand new flow switch could get caught up like this.

It could have been a piece of packing material.

 

[Benjamin]

I have seen things get stuck in the flow switch to create problems like you mentioned as well.

For the pressure spike also might want to look into the bypass. I had the bypass line back to the tank freeze and so of course when I let the handle go the safety relief valve would open and spray water every where. It was a few mins to figure out the problem, but once solved I just replaced the hose and kept going. Since I use old pressure wash hoses to send water back to the tank replacement is just using another unfrozen hose as a replacement.