No Dash Heat Problem Solved

eagle19952 · May 17, 2016, 08:09:38 PM

why not ? ...

Scott & Heather · May 18, 2016, 03:07:27 AM

Craig, thanks for confirming the supply and return. Supply seems to be open just fine. Pipe is hot on downstream side of gate. Return is another issue. Pipe is cold upstream of gate. I scoured your site and saw the drama you went through to replace the gate valve. Yuck. But you said yours were spinning nonstop. Mine unscrew and stop just as they should. I can feel slight resistance and I honestly believe they are working but I guess I can't be sure unless I heat the joint and remove the valve. Oh Joy. To confirm, the thermostatic valve in the front luggage bay that has two air lines and two wires going to it is "normally open" without voltage correct? So if the wires are disconnected it should be open? What about the air lines? Does this valve even play a role in the drivers heat? I know it is an on off valve that helped regulate the main large center heater core....but I assume it can't actually shut off flow to the drivers heat?

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Scott & Heather · May 18, 2016, 03:08:53 AM

Craig, in my 102C3 (bus in question) I have a pull cable on the drivers floor for heat. This is attached to a valve in the spare tire bay that is in line of the heater core tube.

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sledhead · May 18, 2016, 04:51:12 AM

on mine ... the heat system is still stock and the drivers heat blows hot for a short time then it cools down . always done this ? then I turn on the main heat blower fan and the heat comes back to the defroster again as well as the main system . I turn off the main blower fan as it is to HOT then after a short time the defrost fan cools down again ( about 15 - 20 min. ) and I start the cycle all over again . now I only need to do this when it is really really cold out ( like -20 c or colder ) above that temp I get enough heat out of the defrost by itself . I think it is because there is no circulation pump for the defroster system

hope this helps

dave

Scott & Heather · May 18, 2016, 06:40:25 AM

Dave, I think you're right especially since the water will go towards least resistance...in your case your main cabin heater core....larger tubes larger radiator, but mine is removed and the large tube lines capped so the only flow should be through the defroster. Now someone asked me if the circulating pump was removed...I don't even know if I have one. Where would it be located?

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buswarrior · May 18, 2016, 10:57:20 AM

By design, the driver's heater/defroster should provide unlimited heat, on demand, controlled by the valve beside the driver.

The defrost heater core should be able to have unlimited flow of hot coolant, regardless of the coach heat configuration, turned on or off, or whether it has been removed or not.

It is plumbed in parallel to the coach heater core.

In Scott's bus, the control is a vertical plunger mounted on the floor to the left of the driver's seat, with a cable to a valve down below. (In the older buses, the valve is down low in the left side panel and the handle is twisted 90 degrees by the driver)

As long as the defroster/driver's heat lines have not been messed with,
and the removal of the coach heater core has taken place beyond/inside the two T's to supply and return,
the control valve for the coach heat, mounted in the curb side baggage bay, should not interfere,
as it does not block the flow returning from the front.

These MCI coaches don't have an aux coolant pump, the engine water pump does it all.

I concur, I expect you have an airlock, no doubt, a big one, which will require some lengthy opening of the vent on the front heater core. Have a suitable apparatus and storage to collect the coolant you have to blow out to clear this.

And you'll be chasing air out it again, once you get it functioning to some degree.

Hopefully, with the supply side purged, the air on the return side will be pushed through...?

Confirm the cable is fully opening the valve under the driver.

As for adding toe kicks, I would be plumbing them from supply to return, not from supply to supply. You won't get any flow unless the driver's valve is open. Each heater core should be parallel to one another, not parallel to the supply pipe, and in series with anything else....

happy coaching!
buswarrior

jmblake · May 18, 2016, 12:08:50 PM

Scott, I just had my valves apart to relocate the return line and I thought they were opening completely up but they wasn't, They felt like it when turning the handle but it took a little more force to get past that tight spot and they opened completely up. Just a thought worth a quick check. Good luck Jason

DoubleEagle · May 18, 2016, 07:28:13 PM

Quote from: jmblake on May 18, 2016, 12:08:50 PM
Scott, I just had my valves apart to relocate the return line and I thought they were opening completely up but they wasn't, They felt like it when turning the handle but it took a little more force to get past that tight spot and they opened completely up. Just a thought worth a quick check. Good luck Jason

Jason, were your valves the gate-type with flat wedges?

jmblake · May 18, 2016, 07:37:21 PM

Yes they were gate valves, I asume they were original

DoubleEagle · May 18, 2016, 08:06:39 PM

That accounts for the sticking and the uneven pressure needed to open or close, but they do allow for good flow when fully open. Debris in the coolant can interfere with it when it closes and the wedge can get stuck in the channel.

Scott & Heather · May 18, 2016, 09:48:38 PM

Thanks guys. The return gate hasn't convinced me it's working yet. I'll have to keep working on the possible air lock.

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sledhead · May 19, 2016, 04:29:38 AM

Scott

what type of heating system are you putting in when parked ?

dave

eagle19952 · May 19, 2016, 09:38:48 AM

Quote from: Scott Bennett on May 18, 2016, 09:48:38 PM
Thanks guys. The return gate hasn't convinced me it's working yet. I'll have to keep working on the possible air lock.

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the more flow. the easier to remove air... can you plumb in a temporry external pump..similar in function to a fuel primer ?

Scott & Heather · May 21, 2016, 08:13:46 PM

Dave, propane furnace. Update, I drove the coach around for about 35 minutes and the airlock finally yielded and I now have insane heat to the dash heater core. I can't even leave my hand on the heater core it's plenty hot. Now I'll add coolant to the system via the filler and I should be set. Happy as can be

Dave I'll be purchasing a small 40,000 BTU high efficiency apartment furnace for the coach. 96-98% efficient with variable speed blower. Perfect for the coach.

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sledhead · May 22, 2016, 06:46:57 AM

if the price is not too much more you might want to go with a 60 000 btu unit as a little over kill .
in the new coach it has a aqua - hot diesel fired system and works ok , but if I get pissed off with the smell and the noise I might install a propane furnace in the middle bay and use tinfoil 3/4 " board to make a trunk run from front to back for hot air vents with a return or 2 from above . in todays world I think a high efficient propane house furnace is the way to go . but for now I will stay with the aqua -hot system that is there now

dave