Testing Propane Sensors

[off-the-grid]

I have 2 propane sensors on my boat, and one just died.

Returned home to an alarm plus amber light, indicating malfunction. After turning the house bank off and back on, no light on the panel at all indicating no sensor detected.

I'm trying to figure out which one I actually need to replace. On another board a few people suggested holding a lighter by the sensor. Well I tried that trick by both sensors, light the lighter then blew it out while still holding the button so fuel is still coming out, and didn't get an alarm on either one.

If I press the test button on the panel, for the sensor that I still have a green light for, the alarm goes off, indicating that everything is working.

Am I doing something wrong? Held the lighter down there for quite some time. Does that trick not really work?

I have a cat, with one sensor in each hull...and had water in one hull, so I'm guessing that's the bad one. If I remember correctly the light that's out now, is the one that set off the alarm when it got wet.

I'm really trying to figure out if I'm doing something wrong here, or potentially have 2 bad sensors or what, though?

[GordMay]

Water is the most common cause of gas detector failures.
Injecting butane gas (no flame) from a bic-type lighter, for 5 seconds, into the grill of the propane sensor/detector should trigger an alarm.

[off-the-grid]

Originally Posted by GordMay

Water is the most common cause of gas detector failures.
Injecting butane gas (no flame) from a bic-type lighter, for 5 seconds, into the grill of the propane sensor/detector should trigger an alarm.

That's pretty much what I did. Even longer than 5 seconds. Even held my hand under it to try to reduce airflow and trap the gas.

Nothing on either one.

What I don't get is I still have a green light on sensor #1 and it tests ok at the panel?

[Pblais]

What type of sensor is it? Is it a unit tied into the solenoid? Some of the older Sintex units had probelsm where the sensors would go bad and false report.

[off-the-grid]

Yes it's tied into the solenoid.
It's a Xintex S-2A controller and I believe the sensors are both PS-1's.
That's what the manual says it came with, both the old sensors are identical (black vents) and I think the originals.

So, you're saying I very likely have 2 bad sensors, even though 1 is still giving a green light and testing ok?

[Pblais]

So, you're saying I very likely have 2 bad sensors, even though 1 is still giving a green light and testing OK?

That is what mine do. Mine are older S2's. Yes, sometimes the sensors go bad. Mine mostly go off when first turned on and I cancel the alarm and it's fine. I'll be replacing the whole setup soon enough.

[off-the-grid]

Originally Posted by Pblais

That is what mine do. Mine are older S2's. Yes, sometimes the sensors go bad. Mine mostly go off when first turned on and I cancel the alarm and it's fine. I'll be replacing the whole setup soon enough.

Yup, that's exactly what it was. Plugged the new sensor into each port one at a time and the lighter test worked.

[scotte]

Originally Posted by grunzster

So, you're saying I very likely have 2 bad sensors, even though 1 is still giving a green light and testing ok?

Sounds like you already solved it, but this is testable by swapping which plugs the sensors are plugged into. If the problem follows the sensor, then it's just the one sensor that needs to be replaced...

[off-the-grid]

Originally Posted by scotte

Sounds like you already solved it, but this is testable by swapping which plugs the sensors are plugged into. If the problem follows the sensor, then it's just the one sensor that needs to be replaced...

Yeah good point. The problem already existed with both sensors, though.

[off-the-grid]

So any suggestions on how to make a cable run from one hull to the other, that involves multiple turns?

I was going to use the old cable to pull the new one through, but I'm at that point now where there's lots of cursing, as the cable won't budge another inch at either end. I have the control panel removed, and traced the other end up behind the drawer in the aft cabin. Was able to pull a few inches out at both ends, but that's as far as it will go.

Or, is there any reason I can't just cut the old sensor off, cut the connector off the new cable, and crimp it onto the old cable?