Cat Platinum Heaters

[Chuck Newman]

Andy,

If you have cleaned the motor but still it does not spin freely, replace the motor.  If it is a typical vent fan similar to the type in computers, though smaller, once the mechanicals go bad they are done.  Some cleaning fluids will actually attack the plastic components in the fan and make it worse over time.  Trying to lubricate with dry silicone will only postpone the inevitable.

While cleaning the PD tubes, remove the vent cap and blow out the vent line.  Unless the cap is screened, you may have a mud dauber nest or other critters in the vent line creating back pressure, shutting down the heater.

I don't know how old your units are, but remember the platinum catalyst has a finite life span.

Let us know how it turns out.

Chuck

[Eagle Andy]

Hey Chuck  I worked on the dang thing this afternoon after I set 5 railroad ties for the DW . i took  apart the heater cleaned out a little dust and checked the power switch , Had plenty of power did a volt test on the motor ( nothing ) took it out and put it on the bench  motor spun fine . reinstalled said motor and still nothing. Iam wondering if maybe gas valve is bad. I would guess if it was not getting any propane  , or could ther be an air pocket in the line  anyway I give it try again tomorrow and see what I can come up with . Thanks guys for the help  Andy

[Chuck Newman]

Andy,

So if I understand correctly, the fan is not working.  Before the control board will allow catalyst starting heat or spark (whichever they use) or gas valve operation, I am sure the control board wants to see activation of the differential switch.  I haven't worked on one of these particular heaters, but the reason for this is to insure you have proper ventilation for the eventual combustion products before the heater starts.  Obviously, if the differential switch is not operating, you will not get gas.  It serves the same function as the sail switch in a RV furnace.

The differential switches are usually enclosed in a solid metal or plastic round case.  I have tested them in large furnaces by removing the vacuum or pressure tube and blowing air through it to make sure it is clean.  Then, depending on the furnace design, either suck or blow into the hose (with mouth only, no high pressure/high vacuum devices) while attached to the switch.  While doing this with larger switches, you can hear the "click" operation of the switch.  Otherwise you may need to hook up a multimeter.  You can test either by ohms with power off, or by voltage with power on.

The fact that the manufacturer put out the service bulletin to clean these tubes is testament to the fact that frequent heater failures have resulted from debris in the tubes.  And if your tubes are clean but the fan in inoperable, the differential switch still will not function and will not allow starting of the heater.

I haven't seen their fan, but I'm guessing it is no more than 2" diameter and shaped like a computer fan.  The manufacturer should have replacements. I would get two.

Chuck

PS:  I you can smell gas at the valve external to the heater, and your other LPG appliances are working OK, you can generally rule out a fuel pressure issue (13" WC).

[Eagle Andy]

Thanks Chuck , So if Iam understanding you I need to clear the differintal switch by blowing thru the hose into the switch ,or suck which ever side am working is that correct? I did get the motors to work on the bench .

[Chuck Newman]

Sorry Andy, I misinterpreted your previous post.  I thought the fan would run in the heater but the catalyst would not start.

If the fan runs on the bench but not in the heater, you more than likely have a control board issue.  Since these heaters have electrical safety devices  such as a differential switch to detect loss of venting capability, and auto restart functions, it has a control board buried somewhere in the heater.  A relay on the board will drive the fan.

Most of the control boards I've seen use use flat male spade connectors.  Some use round posts with round female connectors.  The female spade connector from fan, DC, ground, sensors, thermostat, etc. slide over the male post.  Sometimes the soldering job isn't that great on these boards and the base of the male connector is loose.  Sometimes broken.  Note the traces on the board generally will be "wave soldered copper" so you won't actually see bare copper traces.  If you do, that's a really cheap design.

That said, most failures of control boards for RV type furnaces, hot water heaters, and refrigerators are due to cracks in the copper traces on the board or cold solder joints -- either causing circuit malfunctions. 

If the control board is not sealed in some material, carefully check both sides for cracks, dirt, moisture, loose wires, burned components, etc.  Gently pull and wiggle all the wires.  If one comes off, that was a poor connection. 

If the board is encapsulated and the wires to the fan appear OK, then it's time to call the manufacturer.  They will probably want to send you a new control board, or return the unit for repair.

I didn't mean to confuse you with yesterday's information.  That information was based on the fan running properly within the heater. 

Any heater or furnace I've seen typically works in the following order (in simple terms):

1. Call for heat from thermostat.

2. Start fire box exhaust fan.

3. Sense that fan is pushing air.

3. Send 3 to 5 strikes from the the piezoelectric circuit while opening the gas valve.

4. Sense flame within 5 seconds.

5. If no flame sensed, lock out piezoelectric circuit and gas valve.

In your case the fan is not running so everything after that will be canceled.   You may still need to follow their service bulletin for cleaning, but that will probably not help until you can get the fan to run inside the heater.

One last thing:  The service bulletin mentioned a "reset button" on the heater.  Try that.  If that doesn't work, perform the serivice bulletin procedure and hit the reset button again. 

Hope this is more clear and helps.

Chuck

[PP]

Check the reset button for obvious reasons and note that when you pull down the front grill it is possible to pull a wire (spade connector) off the circuit board located in the lower left hand corner. Check for these two things before you go any further. When I power mine up, sometimes the fan doesn't kick on for almost a minute, heat follows within three minutes with a little light on the circuit board indicating that gas is being delivered. Only two of mine have the light, BTW, not the little one in the bathroom. Everything Chuck said is on spot. Good luck, Will

[Eagle Andy]

 Chuck & Will


Just checked the Heater circuit board and found nothing unusual , The reset switch is in the rocker switch (reset, off , on . is at the bottom of the front panel . I removed the hoses form the differential switch blew into the low side and nothing then I sucked on the same low side and could hear a clicking sound. moved to the high side and could  do either am I suposed to beable to do the same to the high side?. Thanks you guys  It is always an adventure when I start trying to fix things I don;t no anything about . I guess I better call the manufacture tomorrow.

[Chuck Newman]

Sorry Andy we couldn't do better for you before the dreaded manufacturer call.  Based on a comment from another user, they do the start up routine a little different than most.  Ask them for a maintenance manual.  They are usually full of diagnostic information.  If they don't have a manual, ask them for a copy of the heater wiring diagram.  For future reference.

Good luck.  Let us know what the culprit was.

Chuck

[Eagle Andy]

Hey Chuck , on the contuary you guys helped alot Iam able to open this thing up and but it back together LOL . I was on lease to day and I had my lap top, I talked to the E tech and he helped my understand better what you all were trying to explain to me(Iam a hard study sometimes) I showed him the web site and he gave me a couple of Ideas and things to check , Like jumping the differental switch and making the board think that the motors running . So when I get home on sat Iam going to have another go at it . Thanks again to all of you will let you know what I find . Thanks Andy