My furnace comes on and heates the house for about

Your fitter didn't fix the original issue it would seem. That is the problem with fitters, they cannot repair things.

Ruud Silhouette II Furnace Problem ' DIY Home Improvement Forum (diychatroom.com)

Pull the hose out from pressure switch and check for any restriction ,also clean where hose is connected to from furnace because that will get clogged

Does this unit also have an AC coil installed? Can you check to see if it is dirty or blocked? Although you are not cooling the heated air must still pass through this component. Has it ever been operated without a filter? How many return ducts tie into the unit and is each path filtered? Do you have filters in the individual return grilles? What do the blades on the blower look like? It sounds as if the temperature may be too high if you have to continually reset the high limit. This occurs when you have low air flow.

Bad flame sensor.

Hello, does the igniter glow?

If you have gas furnace, the outside unit will not come on unless you have dual fuel/ gas and heat pump. If you can look at wires in thermostat, if you have no wires going to O or B then you don't have heat pump. Normal tstat wiring for gas furnace and air conditioner. R,W,G,Y and maybe C.

Whew...

Most likely... Your part number (look it up)

RUUD 47-25349-?? (LIKE: 02, 03, 07... etc).
(typically: $10 -$20 range... easy job)

On eBay:


A bit slow getting this answer out on the table...

Sorry anonymous.

BUT for the "over-temp" condition...
Forget the wall THERMOSTAT.
There's usually a switch to option the "DEPTH" of
your heating cycle
(Look up Owners GUIDE for your SPECIFIC MODEL).

The "cool down"... (if there is one) would more
likely be you heaters OWN (fan) THERMOSTAT...

It SHOULD not be getting that much RESIDUAL heat
(possible plenum failure... but hopefully just the switch).

Here you have to ask yourself...
Is IT TIME to get your heater
PROFESSIONALLY inspected...
Pacific Gas & Electric used to do that for FREE...
(but in this new, improved UTILITY climate
we enjoy today... I doubt they''ll do more than TAKE OUT
a few blocks in SAN BRUNO for FREE anymore...
(you might want to check...
(Same DEDIATED workers w/ really poor Management)).

(My opinion: FAT CAT, CRONY, bought & well-paid
EVIL/corrupt Government "oversight" (CPUC)).

There SHOULD also be a HIGH TEMP
fuel shut off "SAFETY" thermostats..

All these should only be handled with skill & knowledge...
as GAS APPLIANCES can be quite dangerous in the
WRONG HANDS...!!

I am just saying...!!

I'm here daily... Comment me back if unclear.

Happy hunting.

Carnac the Magnificent Y

Make sure filters are clean . if they are stopped up the unit will over heat. Lets start there. Russ

I recommend you getting service its a safety thing. the humming is the transformer and is normal.. good luck Tom