Heat on Cab models - Does it work well?

orlo · Aug 5, 2007

Hi:

I have a 3720 cab (A few months (50hrs) old.
I've tried the heat (Certainly don't need it in August but I wanted to try it). It does seem 'warm', but not like a car would be if it was all warmed up (The tractor is). Is it supposed to come out just 'luke warm'? (I'm sure in the winter this would feel great), or is it supposed to come out really hot?

Also, does anyone know if they use a heater core with coolant, or just run the air over an exhaust plenum? If it was the latter I could understand why it's not really hot.

Thanks,

radman1 · Aug 6, 2007

I bought my 3720 cab last sept. In the winter, when the temp got down to 35-40F the cab heat was very poor and the engine would not heat up and the temp gauge remained low unless I put the engine under heavy load. I took it to 2 different dealers about 7 different times. Field rep was involved as well as JD engineers. Initial response from both dealers was, that is how it works. I have other farm tractors with cabs and knew that was crazy and kept pressing the issue. Turbo36 in MI also had the same problem. Finally, his dealer in MI discovered gaps in the corners of the air box on top of the cab. This was letting outside cold air directly into the box rather than thru the filter. One of the gaps was right behind the heater core. These gaps are very hard to see unless you really look for them. Once they were sealed, there was no problem. I could now work in the cab on the coldest days with just a shirt on if I wanted. The test to determine if you have the air box leak is to place suran wrap or other plastic wrap over the filter on the back of the cab. Normally there is a suction through the filter. If the air leak is present, the plastic wrap won't adhere well to the filter.
I did not notice the problem with the a/c in the later summer like I did with the heat in the winter. Do a search under "poor cab heat" and you will find my very long post.
Remember, if you try the cab heat in the summer, be sure the a/c is not on the same time. The a/c can run the same time the heater is on unless the a/c is turned completely off. Also, the a/c cools the entire air box over the cab. It may take a few minutes to heat the cold air box and get good heat. The amount of heat in the cab should be nearly unbearable if the engine is hot and the heater is on during the summer.

sunnyside360 · Aug 6, 2007

orlo said:
Hi:

I have a 3720 cab (A few months (50hrs) old.
I've tried the heat (Certainly don't need it in August but I wanted to try it). It does seem 'warm', but not like a car would be if it was all warmed up (The tractor is). Is it supposed to come out just 'luke warm'? (I'm sure in the winter this would feel great), or is it supposed to come out really hot?

Thanks,

I have a 4 mos old 3720 w/Cab and had the same experience as you with the heat. I spoke to the dealer about it and he told me the amount of heat will vary with the throttle setting. I verified he is right. The heat output is quite a bit greater at working RPM's (~2500) than when at idle speed, but still not not anything like my Silverado truck. I also have a Kubota M8200 w/cab which has a phenominal heating system which is more like the truck. In fact, I have to keep the M8200 on the lower setting in the winter, and the AC on the M8200 also on low on hot summer days. There was another 3720 thread on this topic last Feb/March and the dealer did find something wrong in the roof of the cab (ducting) and I believe there may have been a couple others with the same problem.

orlo · Aug 6, 2007

Thanks. I'll have to try both those tests. When I have tried it it's when the engine is good and warmed up on hot days.

sunnyside360 · Aug 6, 2007

orlo said:
Thanks. I'll have to try both those tests. When I have tried it it's when the engine is good and warmed up on hot days.

Yes, the engine must be warmed up but the higher engine RPM's circulates the coolant thru the heater much better than at lower/idle speed. That's the theory behind it according to my dealer. I'm still not sure if there is a heat problem with mine -- with 2 yrs warranty I have some time to check better in cold weather. Let us know how your test works.

DrainPondDesign · Aug 6, 2007

I can blow out our driveway at minus 30 F in our 3320 & have to cut the heat back after it warms up. But.... the engine is at max throttle when doing this. The heat & AC are in the top of the cab so I'm pretty sure it gets its heat from engine coolant and not the exhaust. I would be very concerned about CO poisioning with an exhaust plenum hot air source.

orlo · Aug 12, 2007

Hi:

Thanks for those suggestions. With the engine at a reasonable RPM (or FULL PTO RPM) the amount of heat coming out is much, much more. Still not what would come out of an auto but much more than what I was feeling.

I guess it must just be a tiny little heater core and if the coolant isn't circulating very fast the blower must just cool it right down.

Manitou · Aug 12, 2007

Orlo On the jodale perry cabs there is tempeture control valve on the overhead panel to adjust the tempeture. Along with the three speed fan switch. Good Luck Garry

DrainPondDesign · Aug 12, 2007

Orlo,

It sounds like you may not be getting as much heat from your heater as I do but without a side by side comparison it is hard to judge.

If you are not TOASTY this winter you should go sit in another 3320, 3350 or 3370 cab & compare it to yours. That is the only valid test that I can think of.

Stay warm.