New NT-30 Woes

[PeteL]

Installed new Suburban Nt-30 over last winter. Used it on maybe 3 occasion this summer and it seemed to work fine, although it was never needed longer than a few minutes to take chill out in AM. Well over this weekend it was needed for longer. It seemed to work fine and brought space up to temp nicely. However, the next day when I turned up t-stat fan kicked on for maybe a minute but then shut off. No sound of ignitor. Turned t-state off and then back on and same senario. Thought maybe low voltage as we had no shore power. Well now home and shore power hooked up and same symptoms. Not sure what would prevent ignitor or valve from opening. Does high limit reset itself if tripped? Would fan still turn if high limit tripped. Bad board?? Dont know where to start?

[Mike Leary]

The fan would still turn, though blow no heat should the board be bad. Hard to believe such a fresh unit would
fail. I would suspect the thermostat.

[whitelight]

We had a similar problem with a newly installed NT30 - we even de-installed it & had it bench tested. The unit ran fine on the bench. Turned out that we had a blockage in the propane line to the heater (spiders?) Anyway, we disconnected the propane line & used compressed air to blow out any obstructions. The heater has been working fine for the last 5 years.

[PeteL]

Will bad t-stat allow fan to run? I can jump the t t-stat, but thought that bad t-stat would prevent even fan from kicking on. If there was a blockage wouldnt I still hear ignitor trying to fire before unti shut itself off?

[Mike Leary]

Originally Posted by PeteL

Will bad t-stat allow fan to run? I can jump the t t-stat, but thought that bad t-stat would prevent even fan from kicking on. If there was a blockage wouldnt I still hear ignitor trying to fire before unti shut itself off?

It's easy to test; I'd do that first.

[PeteL]

Off to jump t-stat. On Suburban's website I noted a lockout mode on the SP. They do not explain how to get it out of lockout mode though. Says fan will run, but no heat in lockout mode.

[PeteL]

Jumping Thermostat did not allow unit to ignite or even try to ignite. Recall the sp will try to ignite 3 times. It did not try even once. I am thinking unit went into lock out mode. I pulled power connector thinking it may reset itself. Anyone have any info on the lockout feature of the SPs

[PeteL]

Spoke to tech at Suburban. Lock out mode just means 30 second shutdown because either sailswitch or limit switch (or both) is open. Knowing Sail switch test meant pulling unit I started with limit switch as it is easy to get to. Removed the two screws holding it in and noticed lower spade terminal came off by itself when pulling from panel. Tested switch and it was closed. Put the two spade connectors back on and reinstalled. Unit now works. I suspect lower spade connector worked itself loose and was cause of problem. Will run it and let it cycle all day to see if it reoccurs

[Jim in Pima]

I just installed at NT30 to replace the burned up NT32 in my 75 Sovereign, found that the exhaust was way too hot..I only had 2 heat outlets in the unit..so added (with a lot of trouble) a 3rd outlet, 3 inch duct. Cooled the unit alot. Should be able to hold hand near exhaust for a moment..if hotter then that something not right. In my case over temp kicked out. Fine now with the added register.