No heat in cab

fruitcakesa · Oct 11, 2023

Is there any one familiar with the under seat climate control on the M6040. the heat stopped blowing hot air and only blows cold. I’m guessing that the heater control valve has failed closed. A few years ago it stuck open and I put a manual ball valve on one of the heater water lines so I could turn it off in the warm weather. This is the opposite. It does still have AC though not very cold.
Where is the valve located and is it fixable or replaceable
Any help would be appreciate

Dusty · Oct 30, 2023

Open the ball valve that you installed when the original control failed. You should have heat. If you don't, then it might be low on coolant, or the heater core could be air-bound and not allowing the coolant to flow through it. If that is the case, then check with your dealer service department and ask how to remedy the problem. The process to remove the air sometimes is easy and other times it is difficult.

fruitcakesa · Oct 30, 2023

Ball valve has been open and coolant level is good, so checking airbound is next. Thanks for the info.

fruitcakesa · Oct 31, 2023

I pulled the seat out to access the heater control lever and was able to get it off the electric control unit. Then with a good stout push was able to move it to the open position. I thought I was home free but not to be still blowing cold. Temperature gauge Is at normal temperature and the rad hose is warm but I can’t locate the WP hoses to check them. I will try looking again tomorrow when it warms up. Oh yes, coolant level is about 2 inches up in the bottle.

4570Man · Oct 31, 2023

Unless the bottle is part of the pressurized system which it’s usually not on Kubotas it’s level doesn’t mean anything. You have to open the radiator cap and check the coolant that way. My Kubota skid steer and GM suburban both lost heater function when the coolant got slightly low.

fruitcakesa · Nov 1, 2023

Thanks for that information. I will check it out tomorrow. I hope I can track this down before the really cold temperatures are here.

fruitcakesa · Nov 2, 2023

Well coolant level is right to the top of the filler neck

I’m am about done.

CADplans · Nov 2, 2023

My Chevy Silverado had the same issue.
There was a clog in a weird location, where the coolant returned from the heater,,

I ended up finding the clog by pressurizing the coolant line going into the heater core
I used air pressure.

It fixed it,, I drove the 1999 truck today, it was cold this morning,, the truck heater was HOT!!