mobilehomerepair.com

ok I will do that today and try and back track it.

Yeah i will try and back trace it today.

Check that burner orifice first, may save you some time.



Thanks,
Robert

OK i havent dont this before ill look and see. Any hints or tips on this other than make sure power and gas are off.?

Turn off power and gas. It is behind the gas valve, small brass fitting with a small orifice. Spiders like to get up in there and inside the spud and build webs.


Just unscrew it and clean out good. (if needed that is)



Thanks,
Robert

ok well i tried that it was clean. Still doing the same thing. I have double checked all the wires and connections even looked for cracks on the exchanger and nothing. I looked down in the heater and saw the lower switch nothing seems to be blocking it or anything. I ran it and that lower switch keeps clicking like its reaching h and L temp.

What are the temp ranges for the limit switch that is clicking ?



Thanks,
Robert

it says 120-20 so im assuming its 120 to 200 but the heat coming out of the vent is only at 104ish and the unit is not getting overly hot i can set my hand on the blower and below the blower and hold it there and the bottom by the little pilot window is a bit warmer can put my hand on there but cant hod it to long.

Hi,

It is supposed be Limit Switch # 7660-3591 which is L150-20.

Meaning it would open and shut down gas at 150* and close again when it cooled to 130*.


What you have is opening at 120* and closing at 100*. That is way to early to be opening.


After cleaning things, more airflow would have cooled things quicker and make it more noticeable is all I can guess without being there.


IF it is not feeling way too hot, worked when jumped and we know it is wrong temp limit, I would replace it and see if that resolves it.


Limit # 7660 - 3591 can be seen and ordered from here by paging down:


http://www.aberdeenhomerepair.com/store ... esults.php


If that did not resolve the issue, I would have an hvac tech come out and do some diagnostic testing.

What temps are on the fan/limit just above the lower limit ?



Thanks,
Robert

Sorry Robert i typed it wrong. The limit switch is a L150-20 and i replaced it with a 1 source they both have the same numbers on them 7660-3591. The fan switch is 120-30 (7700-328).

Then you would have to know temps at time it opens and closes to know if it was working correctly.

It is either doing as designed or it is faulty.



Thanks,
Robert

Robert i must say that im really irritated at myself I was looking at the complicated stuff not thinking about the little stuff. I pulled the blower unit out and that little plate on the bottom was flipped around so i took it out and fliped it the other way and it works just fine. The fan wasnt flowing enough and causing the switch to flip off prematurely. I want to thank you for your help and sticking with me when you could. As many times as i have seen you post on here you are many peoples heros who cant afford alot. You may not hear it from other poeple so ill thank you for them. I hope you know that you are an everyday hero. So again from the bottom of my heart i really want to thank you for your help. if there is anything i can do please let me know. Thank you Robert

Hi,

You're very welcome, happy to help. Thank you for your kind words. Often it is something simple that is just overlooked. That deflector plate will sure enough halt the airflow needed.


You may want to go ahead and get another limit switch, them boogers weaken somewhat when they trip. After tripping as often as it did, I'd want a new one in there for safety.



Take care and best wishes,
Robert

I will go ahead and replace them all. And im not going to leave the site its like a library to me =). Im sure i will be looking for more help on something else. I may also be able to help out someone else.

Sounds good, a lot of helpful info here in the forums, articles, past newsletters, etc.. .



Take care and best wishes,
Robert