How reset Robertshaw 845 controller?

[bossrat]

This controller has a lockout condition according to the manual when the green LED stays off.
Was working fine, I only flushed the tank and turned everything back on.

It said somewhere it could be reset at the thermostat, but I don't know how.

Was working, all voltages seem present, I jumpered the eco switches, no luck.

Thanks!

 

[Master Plumber Mark]

you probably should not have flushed out the heater....
that is usually what causes the problems, just messing with them....
now you are in trouble....

why not post a picture of the control and the whole burner assembly
their sometimes is a simple re-set button on the unit

Which brand of water heater are you talking about??

 

[Sponsor]

 

[bossrat]

Thanks for the reply. It's an AO Smith FPSE75 series.

This tank had so much sediment the water was coming out brown and is well water fed, so it definitely needed a flush unfortunately.
I'd much rather not have touched it an had hot water, but it was even smelling like sulfur. Not any more, but now it's pretty cold!

 

[Master Plumber Mark]

Exactly how old is this water heater that you should have left alone??

Looks like a power vent from probably about 1985 or so....??
I have not seen an aqua-stat on one since I was a younger man.....
I bet you still have a metal chimney with the fan built into the
side of the home too.. Those are rare and most have been changed out
decades ago....

I like the little warning on the unit that claims it is not field repairable.
Most likely you unplugged the thing when you
drained it and it has not been shut down since it was installed...30 years ago

I would say to turn up the aquastat and down a few times then'
give the control a few hard raps with the soft end of some channel locks and see if
it will just come back to life..... it probably wont but you might get lucky

I am sorry but I think you have "screwed the pooch" and bought yourself a new water heater....
a 75 gallon power vent will run you about 2900 installed in our area
You are in Boston so its probably closer to 4k

good luck