2018 Hummingbird 17RB - Furnace problem

[ai2160]

Originally Posted by Rustic Eagle

ai2160,

1) Try removing the outside chrome/plastic exhaust pipe assembly first, then see
if the furnace will back away a little from what appears to be a foil air duct (may
be a slip fit ?). Isn't there an air duct vent cover on the wood panel underneath the
bed that can be removed?

Bob

Thank you Bob! I have a trim tool that use on my cars. Will try that for exhaust.
It is an aluminum foil exhaust duct. It is attached to the furnance on one side (it is not slipped in. It rotates 180 degrees) and on the other side, there is a vent cover underneath the bed, it only comes out after removing the screws but won't go into the frame so I can free the furnace. I will figure it out.

Thanks so much for the pictures and all the help.

[C&R]

Technically it’s under a wood cabinet, which happens to be under a price of furniture. (He says with a hint of sarcasm) My 21QB was set up the same way.

[Rustic Eagle]

Originally Posted by C&R

Technically it’s under a wood cabinet, which happens to be under a price of furniture. (He says with a hint of sarcasm) My 21QB was set up the same way.

Did you ever check the temperature of your wood box panel top during furnace operation (?), I checked mine and resulted in contacting Dometic/Atwood.

Long story short.., my furnace was operating consistently near high temp limits due to the wood box enclosure restricting adequate return air flow back to the furnace's metal enclosure blower motor air flow louvers.

I don't want to 'highjack' the OP's thread on the subject, further reference can be found in posts #157 thru #163 here:

https://www.jaycoowners.com/forums/f...-51005-11.html

Bob

[LuckyDuck]

Originally Posted by Rustic Eagle

Did you ever check the temperature of your wood box panel top during furnace operation (?), I checked mine and resulted in contacting Dometic/Atwood.

Long story short.., my furnace was operating consistently near high temp limits due to the wood box enclosure restricting adequate return air flow back to the furnace's metal enclosure blower air flow louvers. The wood panel top is located 2" above the furnace's metal enclosure and a couple inches below the sofa fabric.

Bob

Bob, I have the same rig as C&R. I’ve checked my furnace when running, out of the same concern. But it seemed cool with no problems. Still not the greatest setup, I think.

[C&R]

I don’t own the 21QB anymore, but it’s good to learn of potential issues with RVs.
Thanks

[ai2160]

Thanks everyone who shared their experience. I fixed the furnace. I have saved a trip to the RV shop and couple of hundred bucks but can't beat the satisfaction of learning something new and doing it yourself! Couldn't have done it without this forum though.

So, what went wrong? This is the furnace model we have: https://factoryrvsurplus.com/product...18801305124933

It is ~3 years old.

- The LED was flashing 3 times indicating ignition lock out.
- Checked the sail switch. We don't have pets and the switch looked clean.
- I didn't hear ignitor clicking, so changed the circuit board and vola! It started to work again.

I replaced the OEM board with Dinosaur board that was so highly recommended on this forum. This is what I have purchased - https://www.amazon.com/Dinosaur-Elec...dp/B009XU7H8Q/

The connections are straight forward and do not need any special tools. Accessing the furnace under the bed though, that is a different story. Once I verified everything to be working again, clauked the outside vent and the furnace is back in business.

[ai2160]

Originally Posted by Rustic Eagle

Did you ever check the temperature of your wood box panel top during furnace operation (?), I checked mine and resulted in contacting Dometic/Atwood.

Long story short.., my furnace was operating consistently near high temp limits due to the wood box enclosure restricting adequate return air flow back to the furnace's metal enclosure blower motor air flow louvers.

I don't want to 'highjack' the OP's thread on the subject, further reference can be found in posts #157 thru #163 here:

https://www.jaycoowners.com/forums/f...-51005-11.html

Bob

I wonder if the excessive heat is the root cause for the premature board failure. I looked at the wood panel above the furnace (our bed basically) it was charred! Any advise on improving the intake airflow to prevent this from happening again?