M22 serial numbers

[Chill Chaser]

I picked up an M22(internal tank) for $40 thinking I would have to tinker to get it running. Plugged in, turned on and out came heat! Great machines and great info on this forum. I'd like to determine the age of this gem, but I can't locate a site that lists serial numbers with date of manufacture. The serial # is 204115.

I need a hand setting the clock for auto run. This M22 has a slide switch for clock set and cycle times. When I move the switch to clock set and press up or down I get "88 88". Is there a special sequence to press to clear the clock for setting or is my PCB getting ready to die? I would like to order some spare parts while they are still available, but don't want to if my PCB is sick.

Thanks.

[HayZee518]

write a email letter to mpi in new jersey. I'm sure they have a listing of serial numbers and manufacture dates.

[hawkins111]

Monitor history

I can not help you with identifying the stove by the serial number. Even when I was a dealer (1997) Monitor would not provide information on dates of manufacturing of older heaters. There does not seem to be any order to the numbers. The enclosed will give you a date range for the different models. As long as you don’t run into an electrical problem, you will be able to get most parts for your M21 as they are very similar to the M422. A main board or an indicator circuit can be fixed by Mathis Electronics for a fair price. The real problem is a fuel pump controller. If you can’t find one in some dealer inventory you are out.

Good luck,

Tom



The History of Monitor

1984
Monitor Products, Inc. is incorporated in New Jersey to market Monitor brand vented heating systems to develop the market begun by KeroSun.
1986
Monitor Products, Inc. becomes a wholly owned subsidiary of Tokyo Boeki USA and moves from Raritan, NJ to Monmouth Junction, NJ.
Introduction of DynaZone air conditioning systems.
1987
The Monitor40 and Monitor21 replace the Monitor30 and Monitor20. The GF12, the first gas vented heater sold by Monitor, is added to the line.
1988
The Monitor41 and Monitor22 are introduced. Adjustable reset and adjustable legs added, and paint scheme is altered.
1990
The KWH124 Instantaneous Water Heater begins Monitor’s entry into domestic hot water appliances.
1994
The Monitor441 and Monitor422 replace the M41 and M22. Economy Plus mode, new paint scheme and longer memory backup are added. Record sales year.
1995
The GF500 Natural Gas and L.P. direct vented heating system mark the return to the gas fired heater market.
Began marketing the MZ line of condensing heating system.
1996
The GF200 is added to the gas fired heater line.
2000
The all new M2400 featuring the first new cabinet since 1987 debuts with a seven-day timer, child lock, new control panel and two-piece flue system. BS indirect hot water tanks are added to the heating system line.
2001
FCX oil fired condensing heating system is added to the hydronic heating line.
2002
The redesigned GF500 becomes the GF3800 which has all the features of the M2400.
2004
The Monitor422 in completely redesigned as the M2200.
The GF1800 replaces the GF200 completing the redesign of the line that began with the M2400.
2006
The MWH180, continuous hot water when you need it, is introduced to the tankless water heater market.
2007
The MWH180EX, outdoor unit of MWH180, is added to the tankless water heater line.
2008
Began distributing the INAX Shower Toilet Seats. Monitor Products, Inc. moved from Monmouth Junction, NJ to Robbinsville, NJ.

[Chill Chaser]

Tom,
Thanks for the timeline. Now I know it's 18-24 years old. Any suggestions on clock setting for this slide switch model?

Appreciate all your info on this site.
Carl

[Chill Chaser]

HayZee,
I'll try that. Thanks for all the great "blow by blow" advice on keeping these units running.
Carl

[hawkins111]

clock set

To set the clock, be sure the Auto button is OFF. Move to Clock Set position. Push Time button, set clock to correct time AM or PM. If the clock does not set with the AUTO off you can go no further. You are aware the stove will cycle automatically when the temp reaches the set temp and shut off 4 degrees over the set temp with the AUTO button off.
If you have a problem with the indicator panel, Mathis Electronics will fix it for a very fair price.

Tom