cruise air unit not heating code's

[Red Hatt]

The boat is located in Va. I have 2 cruise air units the one in the salon is putting out heat at 88 degress and the one below shows a code of L-P-S or it's a 5. and not heating. Does anybody know what the code means. The cond. units are both about 7 months old. Thanks for any help.

 

[SKYCHENEY]

Just a guess. LPS--Low pressure shutdown?

 

[spcoolin]

Yes it looks like a 5 but it is a "S"...It is likely flashing LO then PS...It does mean Lo Pressure.

First thing to look for is water flow thru the condenser (which is an evaporator when heating)
It needs the water to pick up heat from...If the water is too cold then there is no heat (or not enough heat) to pick up and dump into the cabin.

The other reason is low refrigerant charge...But check water flow first.

Steve~

 

[stormchaser]

I've found that with the colder water temps, I cannot have more than one unit on reverse cycle at a time...they error out with the same error (indicating low pressure). I suspect that the very cold water is lowering the pressure too far. I have no problem running one at a time and the problem only crept up after water temps dropped below 35*F....thank god I have aux heat.

 

[Maynard Rupp]

I was told that reverse cycle won't provide any heat if the water temp is below 41 degrees. I always thought that was a joke because our norhern boats are always high and dry when the water gets that cold. You mid latitude guys do keep your boats in the water when it gets below 41. Wow. As Sky said, in the Great Lakes we use reverse cycle as much as AC and the rest of the time we open the windows. By cycling that reverse cycle valve so often we keep it from getting sticky.

 

[spcoolin]

Stormchaser~

Yes 35 degree water is a problem for heat pumps, but if one system will heat...The other/s should as well...They should have no bearing on each other in the way described.

I should also mention that in the later model SMXII firmware versions...Lo/Ps Shutdown is disabled in the heat mode...Instead when it sees Low Pressure it will keep cycling the system compressor till the setpoint is gradually reached.

Steve~

 

[Red Hatt]

Dave, you correct that's is what is happening. As long as one unit is on only-- it appears to operate fine. I thinks thats strange unless it's not getting enough water ??

 

[stormchaser]

Stormchaser~

Yes 35 degree water is a problem for heat pumps, but if one system will heat...The other/s should as well...They should have no bearing on each other in the way described.

I should also mention that in the later model SMXII firmware versions...Lo/Ps Shutdown is disabled in the heat mode...Instead when it sees Low Pressure it will keep cycling the system compressor till the setpoint is gradually reached.

Steve~

Humm...okay, strange...my systems are brand new... I can run any ONE of them all day, every day, no errors...ad in a second one an it errors out within a half hour or so. Also, my controls are brand new (well installed about 1 years ago and are SMX II and they don't do that...can the firmware b updated? Or is it a programmable thing to enable that? The installer (Annapolis Cruisair) seems to have accepted all the baseline programming...I had to do all the customer setup.

 

[Red Hatt]

Dave.
The cruise air units on my boat are acting just like yours. I wonder if the water pump was increased in H.P. to push the water faster through the lines it would run more than one unit with out coding???

 

[stormchaser]

I've only encountered the problem when water temps are below 35...as soon as the water temps hit 35, I can run multiple units...it really seems water temp dependent. I dont know the brand, but she has what looks like a HUGE pump (was on the boat when I got it).

 

[SKYCHENEY]

That HUGE pump is probably an Oberdorfer. They were pretty much standard equipment on the larger Hatts in the late 70's and on.

 

[spcoolin]

Humm...okay, strange...my systems are brand new... I can run any ONE of them all day, every day, no errors...ad in a second one an it errors out within a half hour or so. Also, my controls are brand new (well installed about 1 years ago and are SMX II and they don't do that...can the firmware b updated? Or is it a programmable thing to enable that? The installer (Annapolis Cruisair) seems to have accepted all the baseline programming...I had to do all the customer setup.

The deal is...When the pump starts...It runs thru all units and is the same water, and water temp...Running more than one will not change that unless you have one jumping water to the next which would cool the water to the next more than the first....This would also cause a problem in the summer because the water would be hotter to each unit in the series....I don't think this is the case but like I said...One heating means the others should without problem.

This is not to say that the others may not be lower on freon charge or lacking the same amount of water flow...But if that were the case...It would always be one system (the same system) that would heat when others wouldn't...Not Either Or One that can heat when the other/s cant...They don't affect each other.

I would ask Annapolis (they are a reputable knowledgeable dealer) what they have installed...Now days if the SMX sees low pressure in heat it will not allow you to raise fan speeds above the lowest setting...If you try to raise the fan speed it generally says Lo/Ps and won't allow it....

I guess I can look up or find out how to read what version you have...It's a series of button pushes that we here in Fl don't usually need to know...We just see the response and know what is happening....

Steve~

 

[spcoolin]

Yes Oberdorfer is & was a standard pump for Cruisair...

P1500 BX & P3000BX...1500 & 3000 GPH respectively...

You need 250 GPH per Ton (12,000 BTU)...Add up all systems BTU for a total.

1500 is good for 6 tons
3000 is good for 12 tons

Steve~

 

[stormchaser]

The deal is...When the pump starts...It runs thru all units and is the same water, and water temp...

Steve~

That's where I think you might be wrong. You start off with 35* water going into unit one, if unit 1 is running, the water coming out of it WILL be COLDER than it was going in, so the next unit down the line ends up with COLDER water, and maybe that's bringing the head pressure down too low? See what I mean? Something MUST be up....we seem to have multiple boats with the same issue...and mine are brand new from Annapolis Cruisair (well, almost new, done Decemeber 2008).

 

[spcoolin]

That's where I think you might be wrong. You start off with 35* water going into unit one, if unit 1 is running, the water coming out of it WILL be COLDER than it was going in, so the next unit down the line ends up with COLDER water, and maybe that's bringing the head pressure down too low? See what I mean? Something MUST be up....we seem to have multiple boats with the same issue...and mine are brand new from Annapolis Cruisair (well, almost new, done Decemeber 2008).

Gosh Stormchaser...Not bragging here but...I've only been doing this for 20 + years as a factory servicing rep for the west coast of Fl, and working for the distributor for 11 years as "The Cruisair Guy" ...It's really not my first Rodeo...

If you have a daisy chain of water from one unit to the next with seawater...That will be the problem.

I don't care who did it, and if they did...They did it wrong, it should never have been done that way...Check Cruisair specs if you don't believe me...Check any other Hatteras...Check Any other boat.

Each system or unit should have it's own supply..."NEVER" should one jump to another....They also have a direction that the water should flow thru...The lower of the two connections is always the water inlet, and the upper is the outlet.

Steve~

 

[stormchaser]

Oh, I didnt mean that you were lacking in knowledge, just that you may have been misunderstanding what ai was trying to say..due to MY lack of knowledge, not yours. I dont know for sure if our systems are daisy chained...all I know for sure is that they all work fine if only one is on, if more than one is on AND the water temps are lower than 35...they will error out...not a problem if water temps are above 35*.

Oh, can you upgrade the firmware? Or how do I enable that feature where it cycles on/off if low pressure is detected in heat mode?

 

[spcoolin]

Sorry Dave...Guess I could have said that a bit differently...

I would however follow up to find out if somehow the hoses got re-routed to the improper inlet/outlet causing what we are talking about...I have seen it happen where someone got confused causing the daisy chain, and or reversed flow direction...

If done that way it will not only cause problems in heat just as you describe yours...But it will also adversely affect cooling performance in the summer too.

To be a bit more descriptive...Freon enters the condensers where the water exits & flows the opposite direction...Even running the water backwards from the designed direction will affect operating pressures, and thus performance in both heating & cooling...

I do agree that 35* water is pushing the envelope for reverse cycle heat, but I still maintain that if you can get heat out of one system with that temp water...You should be able to get out of the other systems too...Even with all systems running.

As far as your firmware question...I've got a call into the factory, and am waiting on a return call...Like I said...I don't have much call for that info so I need a bit of a refresher to give you the up to date info...I'll post back when I get an answer.

Steve~

 

[spcoolin]

Ok...A bit more description straight from the Cruisair factory's mouth...

If your 2 year old units have the telephone type connectors for the temp sensor & control cable (and they should because all units built after 2001 did) then you have the new A-288C (smaller) circuit board...The firmware is not update-able as it was in older A-281 boards that had pin connectors for the cables.

Basically you should have the newest firmware...

The description of what it does in the heat mode when it sees low pressure is quite lengthy, and unless you know refrigeration theory it may not mean much to you...Yes yours should go to low fan, and a press of the fast button will make the display show Lo/Ps if there is low pressure at the time you press the button, and it also will not allow you to raise fan speed manually.

This algorithm was programed into the software when Self Contained units using Rotary compressors became main stream...Rotarys do not act like a piston type compressor does for heat pump use and have a slight problem doing so when compared to the older piston compressors that continued being produced for the split systems...However, in an effort to standardize controls systems...They changed all controls...Piston types didn't have a problem with the change, and the rotary's required it...

I was wrong on the not showing Lo/Ps in the heat mode...Sort of...

I never get to see this because of our water temps here in central Fl, but according to Cruisair...It takes about 2.5 hours to show up, and the system will go thru a bunch of things (cycling) to get there to display it (part of the long description I was speaking of above but it relates to # of times and when it will cycle the compressor )

I am told that they state in the manual (maybe not in enough places) to never run your system in heat mode with seawater any less than 38*...That's the absolute bottom limit with SMX...Older systems with the manual controls you could not run in temps that low...Maybe like 42*

Colder temps (although you may get some heat out) can & will cause the seawater coil to ice internally...When this happens it will cause the water coil to expand & rupture...Effectively ruining the complete system with seawater mixing with the refrigerant & oil throughout the system.

Again...You should still be able to get heat out of more than one system at a time (water temps over 38* with SMX)
My point being...Given that each system has proper flow & refrigerant charge, they should all work the same in the same environment...One should not affect another, and if they do...You should confirm your water flow direction & be sure no units are daisy chained...

Steve~

 

[Red Hatt]

Steve,
You are correct in your statment about the water temp etc. I called the factory in Va, and they told me exactly what you have written. I called the boat yard and told them to witerize the units. I don't want them to freeze and ruin the units. Thanks for all you help.