Jabsco electric and New A/C issues

[Adamerica]

Couldn't find previous threads on this, 'Use the Forum' the voice said.......

Jabsco- replaced motor about 7 months ago, no issues.
Boat went on the hard for about 2-3 months for maintenance.
Now when splashed, we notice some apparent leaking between base of bowl and floor, evidenced by the blue holding tank additive we use. Holding tank is empty, no vent issues that I know of...
Oh yea, also.....water doesn't stay in the bowl after full flush since the new motor went in. You have to push button prime it and get some water in the bowl before use. But works fine otherwise.... Joker valve? (Which is new to me....)

A/C
Newly installed 16K BTU Dometic......
Working fine with fan 'on' setting 6, thermo turned to 75....
Arrived at slip, set fan to 'auto', and moved the temperature up to 80 degrees. (Southwest Floriday, BTW..)

Came back two days later to find the unit frozen up, and a temp of 101 down below... switching off the unit, within an hour at that interior temperature, unit was 'back to normal'...turned it on, plenty of cool air, pump working famously, set fan to 6 and 'on' this time...going back tomorrow for a check up on the system.
Don't like fan 'on' all the time, shouldn't need that.
Any suggestions as to what caused this?

[peghall]

Which model Jabsco?

However, without knowing I can tell you that it's not supposed to hold water on "full flush," only on the "just bring water in" setting.

Now when splashed, we notice some apparent leaking between base of bowl and floor, evidenced by the blue holding tank additive we use.

I think you mean between the base of the bowl and the base it's mounted on. If you didn't also replace that seal, it's most likely the reason for the leak...unless you did replace it but over-tightened the nuts when you set the bowl back on the base. That will cause the seal to pucker around the nuts, causing leaks around 'em. Backing 'em off just a LITTLE should stop the leak unless the bowl has been down long enough for the puckers in the bowl seal to become permanent...in which case, you'll have to replace the seal again. And btw...same is true of joker valves. The flange is the gasket that seals the connection between the discharge fitting and pump. So only tighten any bolts that go through a rubber seal just barely snug...test for leaks...tighten just a wee bit more...test...and quit when it doesn't leak.

Someone else will have to help you with your AC problem..that system is above my pay grade.

--Peggie

[Bean Counter]

Jabsco. If the dye is coming out then there are 5 places the leak can come from.


1, Hose clamp to discharge port is too loose, sometimes need two clamps. Or it has been over tightened and split the plastic allowing drips to come through.
2. Discharge port that contains the Joker valve. If the screws that hold this on have been over tightened then it too can split the plastic and cause a very slow leak.
3. Macerator pump O ring, this may not have been seated properly on installation or is pinched.
4. Screws to hold macerator in place have been over tightened and split the plastic
frame.
5. Toilet bowl flange not sealed properly (as in previous post)


You need to observe all these areas closely and not assume that because you can see dye on the floor it is coming from a certain point.



There are a bunch of videos to assist for example :

https://www.youtube.com/watch?v=BuHMYCEEqWk

[Coolerking]

The fan must run when the compressor is running, or the evaporator will ice up.

[Adamerica]

so is it possible the 'auto fan' relay (if there is one) isn't working?
can't think of any other reason

[Coolerking]

What model AC and which display do you have?

What are the dimensions of the return air and discharge grills, what size is the duct?

[Mojadito]

On A/C systems, air flow is everything. When an A/C unit ices up it is due to lack of airflow. Most common causes in order:
Dirty Return Air Filter

Restricted or too small Return Air Grill, MUST be at least 160 square inches

Restricted or too small Discharge Grill(s), MUST be at least 80 square inches

Restricted or too small discharge Ducting, MUST be at least 7” Diameter, or on split systems, must total at least 39.5 square inches

It is quite common to have undersized air handling equipment, even directly from very good boat builders.

[a64pilot]

On my system auto fan only kicks in higher fan speed as the set point and the sensed temp diverge, which really only makes more noise, fam speed does little to add extra cooling.
Icing up is almost always restricted airflow, it can be refrigerant level low, but most often it’s a dirty filter etc.
On yours if you normally run it on some other fan setting other than low, it’s possible that your airflow is minimal but within limits, until low fan speed is selected automatically, the its not enough and ices over.

[Coolerking]

Originally Posted by Mojadito

On A/C systems, air flow is everything. When an A/C unit ices up it is due to lack of airflow. Most common causes in order:
Dirty Return Air Filter

Restricted or too small Return Air Grill, MUST be at least 160 square inches

Restricted or too small Discharge Grill(s), MUST be at least 80 square inches

Restricted or too small discharge Ducting, MUST be at least 7” Diameter, or on split systems, must total at least 39.5 square inches

It is quite common to have undersized air handling equipment, even directly from very good boat builders.

All of the numbers you posted are for a specific size unit, I have installed many ac units, both split and self contained, with ducting sizes from 4 to 9 inch.

Bottom line is on a DX system, the fan has a minimum speed setting, given that the duct and grills are correct.

The fan must ALWAYS run when the system is being asked to cool.


Of course this doesn't apply to tempered water systems.

[KadeyKrogen38]

A HVAC unit freezing up is a sign that it is low on Freon.

[a64pilot]

Originally Posted by KadeyKrogen38

A HVAC unit freezing up is a sign that it is low on Freon.

Yes but be sure to be really certain it’s not air flow, cause most newer units don’t even have service ports, they have to be added and that’s not trivial.

[Frankly]

Just installed a new Webasto 12,000 BTU in my shop (running on well water). Fan runs all the time as the compressor cycles on and off depending on settings and conditions. Duct work almost non existent. Woks fine but wish there was a setting that allowed blower and compressor to run together, but have not found it yet.


As others have said insufficient air flow would be first place to start looking. And the unit has no charging ports so gas charge checking going to get complicated.


Frankly

[Coolerking]

Originally Posted by KadeyKrogen38

A HVAC unit freezing up is a sign that it is low on Freon.

This is not always true.


Most modern AC systems have a low pressure switch, which will shut the unit down after a few restarts.
Most icing situations are from a lack of heat load into the evaporator.
There are many causes of that.
The reason that most marine AC systems have an "always on" fan, aside from when the compressor is on, is that it gets its inside air temperature reading by pulling air back to the evaporator.
In this way it knows when to cycle back on.
You can also easily ice the coil up by leaving the setpoint at a # that is unreachable, turning the fan speed to low, and opening the doors and windows to the world.

Trust me , I've seen it all.

[Adamerica]

Thanks to all for the great pointers...
Gasket ordered for Jabsco-
Ducts and grills being reworked on the A/C....

All good - Thanks again!

[a64pilot]

Originally Posted by Frankly

Woks fine but wish there was a setting that allowed blower and compressor to run together, but have not found it yet.






Frankly

There isn’t one, fan runs 24/7. Some of the more expensive systems, King for example do work like a house system, that is fan is off with compressor.

Thirty or more years ago I had a Sears Window unit that would turn the fan off with the compressor and then turn the fan on an run it for one minute every so often to sense the temp.
Seems to be such an easy thing to do you wonder why it isn’t done, or why not have a remote temp sensor option that would allow house type of operation, I believe that is what the King system does.
https://king-air.net/marine_ac.html