Got AC but no heat

[GJD]

Curious about the Cruisair unit in the galley/forward stateroom. The AC works just fine but the heat doesn't work. Fan operates no problem, it's just the condensing unit in the star engine room never kicks on. Is there a quick punchlist of things to check to look into this? Is this another one of those 'cubes' that could be bad in the circuitry box that's tacked to the port bulkhead? Thanks for any insight.

 

[Angela]

I have the exact same problem with my salon unit. However, I just decided I didn't need heat. But, I'll be interested to hear that the AC gods have to say. I have visited this subject in the past, and didn't really get an answer that fixed my problem...that's when I decided I just didn't need heat (Miami).

 

[GJD]

Lucky you, Miami. Cincinnati wants a little something to take the edge off though!

 

[Angela]

Lucky you, Miami. Cincinnati wants a little something to take the edge off though!

Yeah, that's reason #1 why I don't live there any more (Eaton and Dayton, OH).

 

[SKYCHENEY]

Yeah, that's reason #1 why I don't live there any more (Eaton and Dayton, OH).

Funny, I went to school at Miami University(the real one in Ohio) and remember a saying about girls from Dayton and Eaton but I can't repeat it here

 

[wmassey9]

Question: Did it heat prior to now? Some were made as cool only, not many.

 

[GJD]

Yeah, it used to work but it doesn't now.

Sky at Miami and Ang in Dayton. Boy oh boy. As you know then, winters aren't horrible here but we do get our fair share. Sky, I always wondered how you were the smartest guy on the forum!

 

[SKYCHENEY]

Yeah, it used to work but it doesn't now.

Sky at Miami and Ang in Dayton. Boy oh boy. As you know then, winters aren't horrible here but we do get our fair share. Sky, I always wondered how you were the smartest guy on the forum!

Greg,
You must be a Redskin grad as well, huh? What year?

As far as the heat, it sounds like maybe a control/thermostat issue. What controls do you have?

It seems if the reversing valve was stuck it should still turn on the compressor, but on cool and not heat.

 

[Brian Degulis]

My limited knowledge of AC say's reversing valve. I think you can tap on it to try and free it. You need dave or Krush for a real answer though.

Brian

 

[GJD]

Sky, I'm a WKU Hilltopper. Know a lot of folks who went to Miami though.

The thermostat looks like the original. It has a twisty knob on the face of the control to adjust the temp and immediately to the right of that are a couple rocker switches that flip uo and down, one's for heat/ac other is for fan speed I think. I'll get a picture of it right away so everyone can see for sure.

 

[eze2bme]

Make certain that your freon charge is correct ... low freon and you won't get heat.

 

[SKYCHENEY]

If I read the first post right, you are saying that the compressor does not even run in the heat mode. I don't think this would be a rev valve or freon issue. If it was low freon, it should still try to start. If it was a stuck rev valve, it should run, but it would put out cold air instead of warm.

 

[GJD]

That's right, the compressor doesn't even try to kick on or anything. At least not audibly.

 

[SKYCHENEY]

Sound like something wrong with the thermostat unit. Maybe the heat switch is bad. Do you have a wiring diagram?

 

[Angela]

That's right, the compressor doesn't even try to kick on or anything. At least not audibly.

Me too!

 

[krush]

Figure out the wiring diagram and open up the thermostat (or tap in elsewhere) and manually do a "call for heat". It will mean connecting a few wires together.

Always check the simple things first...like making sure the thermostat is actually calling for heat.

If none of this makes sense, pay somebody that knows what to do LOL.

 

[spcoolin]

Hey Guys....New here...I'm a trained Cruisair guy doing mostly marine A/C for the last 23 years (11 of those was with the Cruisair distributor here in St Pete Fl)...Also worked for a Hatteras dealer during the 80's...

Hope I can help out from time to time here...I know you may be skeptical of me spamming, but I assure you that is not my intention...I see Pascal is a member here and I believe he has seen my posts elsewhere...Anyway...

On to the problem the OP posted...Cooling but no Heat with no compressor...

As others have stated...The description points to a T-stat problem not sending the signal to start the compressor...

I do need to know what T-stat (control) is installed...Depending on the Hatteras's age (and if it has been retrofitted to digital) it could be a few...

Hatteras used a 3 knob manual (Cruisair), and a Honeywell (looks like a home t-stat)

The Honeywell was used in conjunction with a 2 knob system Mode & Fan speed control (one knob for each) There were also a few variations of this setup...and the Honeywell was never very accurate being a bi-metal disc type sensor (can't use mercury on a boat due to rocking & rollin)

Let me know what you have...It can be as simple as a calibration issue...

Steve~

 

[Angela]

I've got the 2 knob manual (Cruisair) control (contols fan and heat/cool/fan), and a Honeywell thermostat. No heat anymore.

 

[doc g]

If it's the "old" style Honeywell I think they are line voltage stats be carefull as you have 110 or 220 at the stat. If I recall correctly cool is a normally open circuit and heat is normally closed. So if the RV is not getting voltage it stays in cool mode. My stat had the designations on the back of the stat when I took it off to replace and upgrade my unit to digital control . I would kill the breaker and pull the stat out of the wall and look at the back to see , you could manually close the circuit for heat by just jumping the wires to each other there .......Pat

 

[spcoolin]

What happens when you rotate the Honeywell knob on top to it's warmest setting (needle out of sight) and rotate the fan/cool/heat knob to heat ?

Like I said earlier...The Honeywell's were never very accurate (even when new)
What you are looking for is a audible click when raising the temp on the Honeywell.
It's also important to note the actual cabin temp because they are set to only operate within a certain temp range...Meaning if it is not cool enough in the cabin...You will not get the click to energize the compressor...

Reason for this is they don't want the system operating in heat mode with much more (if any) than a 80 degree cabin temp...The Honeywell had around a 5 to 6 degree differential (if not more at times) so the cabin temp would need to be below say 75 or even lower before you get the click available...

I know...It's not ideal and Hatteras was the only boat I know of that used a lot of the Honeywell's (I think Ocean used a few, but not like Hatt did)...Cruisair found that control just for them (at Hatteras's request) so that their owners would have a control that might be closer to what they have at home in operation....Thing is it was never as accurate as the 3 knob that placed a sensor in the return air path.

I have not seen one in quite some time (as most here have been retrofitted to SMX or SMXII digitals) but if memory serves me...They had an adjustment inside that can change the operation range a bit...

I'm reasonably sure your issue is with the Honeywell...Let me know if you hear the click while raising the temp...The system does not need to be running for this test....

Another test you can do is run the system in cool till the cabin gets cold...Then try again for heat....If the compressor then comes on you will know it's calibration of the Honeywell.

If that's the case...I'll try to locate an old Honeywell around here to refresh my memory on what you can do to change calibration.

Steve~