Ask Me Help Desk - Mobile home furnaces

Have 1970 mobile home which I bought when it was 3 years old.. it had natural gas furnace.. which worked great for many years. A couple years ago someone checked it and it had cracks in the heatbox so had to get new one. When removing the old one there was some type of thin metal 2 sided thing which went down through floor. When installing new Miller gas furnace it didn't have (whatever that was) and just sat over the opening in the floor... which blows through ductwork. Problem is now the furnace just draws so much air from inside the trailer.. that it pulls cold air from anywhere possible.. around sliding glass doors.. entry door.. also if there is a fire in the fireplace... it pulls the smoke down the chimney and into the trailer.(the old furnace never did this) Is there any way to correct this problem.. the furnace is actually in a cupboard with a door and door has louvers for air flow... a thought I had was.. around the flue pipe going through the ceiling.. the hole for the pipe is much bigger than the pipe.. so there's quite a big of open ceiling around the flue.. IF the louvers were closed off on the door... would it be possible for the furnace to then draw air from up above the ceiling.. and stop drawing air from the inside of the trailer.? Also if the temp ouside is really cold.. and thermostat is on 70.. the furnace blows warm air.. while sucking in cold air.. and just can't reach temp and just continues to run. Hope you have answer and Thanks

Quote:

Originally Posted by herblee

Have 1970 mobile home which I bought when it was 3 years old..it had natural gas furnace..which worked great for many years. A couple years ago someone checked it and it had cracks in the heatbox so had to get new one. when removing the old one there was some type of thin metal 2 sided thing which went down thru floor. When installing new Miller gas furnace it didnt have (whatever that was) and just sat over the opening in the floor... which blows thru ductwork. Problem is now the furnace just draws so much air from inside the trailer.. that it pulls cold air from anywhere possible..around sliding glass doors..entry door..also if there is a fire in the fireplace... it pulls the smoke down the chimney and into the trailer.(the old furnace never did this) Is there any way to correct this problem.. the furnace is actually in a cupboard with a door and door has louvers for air flow... a thought I had was.. around the flue pipe going thru the ceiling.. the hole for the pipe is much bigger than the pipe..so theres quite a big of open ceiling around the flue.. IF the louvers were closed off on the door...would it be possible for the furnace to then draw air from up above the ceiling.. and stop drawing air from the inside of the trailer.????? Also if the temp ouside is really cold..and thermostat is on 70.. the furnace blows warm air.. while sucking in cold air..and just can't reach temp and just continues to run. Hope you have answer and Thanks

The new Miller furnace you bought back then had to be installed with a NEW Miller Roof Jack for the new furnace and associated new flue pipe to allow combustion air into the new Miller furnace. If this was installed when you installed the new furnace then you would not be having this problem you are having now. Mobile home professionals know this and I guess whoever installed your furnace did not read the install instructions. Mobile home furnaces are different from a regular home furnace and this does cause many a misunderstanding.

The link below goes to a professional mobile home furnace site. The people who manage this site are mobile home professionals and can help you. NOTE: You cannot change or modify the way this system works except to use the exact factory parts that are installed as per the manufacturers instructions, Post your question there under Nordyne/Miller/Intertherm posting area. I just hope the proper parts are still avaiable for your furnace. One other note. With the furnace being installed in a unsafe manner you are lucky that you have not had a fire since your insurance company looks for this type of problem during there fire inspections. Many mobile home owners have had there policy canceled after a fire when it is discovered there is no HUD required outer air supply/flue pipe cooling jacket installed on the furnace. Make sure to post your exact model and serial number along with your problem.

Here is the link.

Index page

To hvac1000 Don't know how to message you... so am doing it here... I was the one asking about the Miller furnace recently for the 1970 trailer Herblee you said it needed installed with a new miller roof jack... I want to say thank you SO much... you were the first one to come up with the solution to the furnace not working properly... I was going to have a furnace man come out a while back.. but he said all that's wrong is you need to change the wire so the fan speed is lower... Well that did nothing. SO Thanks so much... I ordered the part from the site you mentioned. Herb

I come up with the correct answer once in a while. LOL Glad you have figured it out. Those are a good group of people on the mobile home site.

To hvac1000... Hello this is Herb (again) I had asked you about the miller furnace that we put in (m1 series) in oct. 06.. which never worked properly.. and you told me about the new miller roof jack which is going to be put in... I looked all through the manual that came with furnace.. now I see that it also says that a duct connector should be instaled under the furnace. Well that wasn't done either... it is just sitting over ductwork (as the old one was). Do you think this would be a problem? If so I can order that part too. Not to shift the blame... BUT my nieces husband installed this furnace in 06.. and I guess he thought just replace everything back to the same way the old furnace was... and didn't bother to refer to install manual. No more questions... and thanks a lot. Herb

HVAC has no PM or e-mail options open so try this recnt post to send him a question or note. https://www.askmehelpdesk.com/heatin...ew-475554.html

To hvac1000... Hello this is Herb (again) I had asked you about the miller furnace that we put in (m1 series) in oct. 06.. which never worked properly.. and you told me about the new miller roof jack which is going to be put in... I looked all through the manual that came with furnace.. now I see that it also says that a duct connector should be instaled under the furnace. Well that wasn't done either... it is just sitting over ductwork (as the old one was). Do you think this would be a problem? If so I can order that part too. Not to shift the blame... BUT my nieces husband installed this furnace in 06.. and I guess he thought just replace everything back to the same way the old furnace was... and didn't bother to refer to install manual. No more questions... and thanks a lot. Herb

No Herb, click on the link I gave you and then post your message

In the install instructions does it say why it is needed?

A few weeks ago you advised me to install a new miller roof jack as I was having problem with gas furnace... I bought one from aberdeen and in stalled it yesterday... boy it was hot on that metal roof!! What I wanted to tell you was that when I took the old one off... there was an inner pipe that connected to an inner pipe inside the furnace... I hope that doesn't mean that what I removed was the same set up as when I installed. I won't know how it performs until the cold weather. One quick question... that's an older trailer.. so the furnace fits inside a cupboard... the door has a metal louvered section on the upper door... about 17 by 17 inch. With the newer furnace.. would it need something larger than that for the intake of air?? Also the openings in the louvers are not very large... even with the old furnace.. when it was running and you would close that door... it would almost suck the door closed. Thanks again.. Herb

Quote:

Originally Posted by herblee

A few weeks ago you advised me to install a new miller roof jack as I was having problem with gas furnace ... I bought one from aberdeen and in stalled it yesterday.... boy it was hot on that metal roof!!! What I wanted to tell you was that when I took the old one off...there was an inner pipe that connected to an inner pipe inside the furnace... I hope that doesnt mean that what I removed was the same set up as when I installed. I wont know how it performs until the cold weather. one quick question... thats an older trailer.. so the furnace fits inside a cupboard... the door has a metal louvered section on the upper door...about 17 by 17 inch. With the newer furnace .. would it need something larger than that for the intake of air???? Also the openings in the louvers are not very large... even with the old furnace..when it was running and you would close that door...it would almost suck the door closed. thanks again.. Herb

. First I do not think I got an answer to your last post see here

https://www.askmehelpdesk.com/heatin...ml#post2377275

To make it easier can you snap some pictures of the louvered door. While trailers are considered very high static units the sucking the door closed situation is not a good sign.

To post pics go to advanced and hit the paper clip sign and pick the pictures off your computer.

Try to keep all your posts on the same link. We have 3 or 4 different posts on the same thing. I will try and combine them here.