VCCA Home Forums TECHNICAL - 1945 AND NEWER 1946-1948 Heater hoses

Am I correct in routing the heater hose on my 47 from the thermostat housing to the top tube of the heater, then from bottom tube to the water pump ????

That would look correct...It would seem...I guess you no longer have an under-seat heater/under-dash defroster combo...? Or never had one...? The diagram I have for that install would be "water pump to the top inlet on the defroster"..."Lower defroster inlet goes to under-seat heater"..."Return under-seat heater hose connects to the thermostat housing"...

I know...A lot of help I am, huh...? Sorry.

The under-seat heater is in my Fleetline 4 dr. I have those hoses going from thermostat housing to top inlet of defroster unit, then from there to under-seat and back to w/pump. Going to the defroster first gets the hottest water for clearing the windshield when the cars were driven in cold weather. My thinking was to follow the same path as the engine cooling system. Hot water enters rad at the top and exits the bottom as it cools.(the two inlet/outlet tubes on the small defroster are so close I really don't think it makes much difference on that unit but an under-dash heater tubes are further apart)
I was going to use the same logic for my recently reconditioned under-dash Deluxe htr I'm installing in my 47 Aero. Of course I could be entirely wrong in my thinking. You mentioned a diagram. Is that something Chev published for installing heaters and hook-ups ??
All this fuss and I'll most likely never drive either one in cold weather were it might make a difference !!!

Gene had me install the hoses so that the water pump hose went to the top of the heater and the bottom heater connection went to the thermostat housing. I forget the logic behind the hook up. Hopefully, Gene will weigh in on this. :-)

I would suggest having the hot water enter the bottom and exit the top. The reason for that is that it will allow any air in the system to be pushed out of the heater. To have the hot water flow from the top to bottom may trap air and reduce the effectiveness of the heater.

Yes, I think we're in step here...I'm going from old photo's of the original routing...And that's what I get, too.

Here are diagrams for the hoses and water flow in 1951 firewall mounted FreshAir and Recirculating heaters. Don't know if they can give you any insight into your '47.

> 1951 Passenger Car Air Flow Heater Hoses
> 1951 Passenger Car Air Flow Heater Valve
> 1951 Passenger Car Recirculating Heater Hoses
> 1951 Truck Air Flow Heater Hoses (1)
> 1951 Truck Air Flow Heater Hoses (2)
> 1951 Truck Recirculating Heater Hoses

- Lonnie

Well, that's different...The pump ( lower hose ) in this diagram appears to pull the water through the system, rather than push it thru...

Funny, isn't it...? How Gene lets us "roll this around in our heads for a while" before setting us straight...?

Actually the outlet of the pump is into the cooling passages of the engine and out the upper hose. So the coolant is pushed though the heater. Not like the radiator that has only gravity to assist flow to the inlet of the pump.

So, the "hotter" water would be from the thermostat housing hose and should be connected to the bottom inlet of the heater core...(?)

The hottest water is from the engine to the radiator. So the thermostat housing area or back corner of the head are best to take for heater. Inlet of water pump is coolest as the water has been cooled by radiator. If the water flow in the heater is bottom to top then any air will be swept out.

Thanks to all who replied. Looks like I will run the hot water in the bottom htr tube and out the top. I never thought about the possibility of air getting trapped.