AC unit error LPF

whatfiero · Jan 3, 2017

LPF. If that is low pressure Freon [probably is] could simply be refilled if you have access to proper refrigerant type most older systems are r22 and you'll need a gauge set to install but if it's totally empty it has a bad leek and that will be a'short term fix and unless you can braze a New evaporative coil into unit . But if it's 143a that and install tool can be had at auto parts store but but you'll need adapter to go to 1/4 Schrader valve. Check internet for temperature charts for fill so you don't over charge

DayDreamer41 · Jan 3, 2017

Pura Vida WI said:
This fall my wife and I purchased a 2005 36. During the sea trial the air conditioner reported a “LPF” error. The AC is a Marine Air Systems Vector Compact.

I am wondering if correcting this error by recharging the system is DIY project or do I need a HVAC technician? Has anyone else dealt with this error? Can this be caused by anything other than low coolant?

I would check your seawater pressure switch first, before looking at freon, a unit that young should not be experiencing freon issues.

Link to a PDF Manual
https://www.google.com/webhp?source...q=Marine+Air+Systems+Vector+Compact+LPF+fault

Gunni · Jan 3, 2017

Yes, common thing. You prime the A/C seawater pump and restart the system.

ice breaker · Jan 9, 2017

I would add a caution to this AC issue. R22 systems require an EPA lisc to charge/work on the system. If you are un licenced and get caught by the EPA, it is a $25,000 fine. It does not happen often, but they do catch a few people every year.

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SEMPERAVANTI41 · Jan 9, 2017

I do not believe there is a "seawater pressure switch". There is a low pressure switch in the gas or freon system. When the freon pressure drops below a set pressure it shuts down the system and displays the trouble code "LPF". If you were testing the a/c system with the boat in very cold water as you have in WI in the fall, the raw water may be so cold as to lower the pressure of the freon to the point the low pressure switch closes. Until the raw water warms up it may not be possible to get an accurate reading of the freon supply either by the "LPF" display or even if a set of refrigeration gauges are hooked up by a technician. If you could supply the raw water circuit with warmer water, around 60 degrees, then you could start to get an accurate reading of your freon supply.
I suggest you wait until you can supply the raw water circuit with warmer water and see if the system runs without the "LPF" trouble code. If you still get the trouble code you will need to attach refrigeration gauges to get an accurate reading on your system. It is not possible to correctly charge a system without.

SirMichael · Jan 24, 2017

You might be able to save your self some money by purchasing a Freon leak detector. They are available on Amazon and eBay for $20-$25. Basically, patiently go over all of the connections and lines and try to find the leak.