StaRite SR400 error code 05

[fletchusmc]

Have an SR400 converted to propane. Approx. 15 years old. Just finished replacing the: Tube sheet, igniter, insulation, thermal regulator, new manifold with new sensors and bypass valve, Ignition control module, main circuit board and finally the stack flue sensor. Circuit board is rev. 8 and lights up normally but when I start the heater the fan comes on, the heater fires and begins heating, runs for about 30 seconds-1 minute then stops with the error code 05 and SFS light on back of board. Have checked the exhaust temp with an infrared thermometer, never exceeds 250 f. Everything has been replaced that I can imagine causing a problem. Btw, the propane tank is full.
I have seen other people referencing holding the pool on button down to display flue temperature, but that doesn't work with my heater. It flashes 33 then shows 27. Should it or is that true for newer heaters only? Does that possibly indicate a bad control circuit board? Is there a way to test?
The new Stack Flue Sensor tests normally, ambient temp shows around 3.6 M ohm and the resistance goes down as the sensor is heated. I am not too bright when it comes to electronics so at the risk of sounding stupid I will ask if it should show continuity? Neither the old one or the new one does but they both display the appropriate resistance.
I have not tested the thermal regulator yet because it is brand spanking new but since everything else is also I guess I should?

At my wits end,
Tony

 

[ps0303]

Just curious, why would you spend all that money on a 15 year old heater?

 

[fletchusmc]

haha, creepage, started out with one part which led to another and then another. I am only out $1125 so far, and with the exception of the blower and gas valve I have a new heater. Just wish it worked. But seriously, every step seemed like it should have been the fix. If the heater documentation were less cryptic and more detailed it would help eliminate needless grasping at straws. Specifically, why have an error code and diagnostic light if they can mean any of 3 or 4 problems? Why not explain that it is isn't the stack flue sensor if the exhaust gas does not exceed 400 f. And why not explain the logic of saying it's the thermal regulator? Why would the thermal reg cause the error? Because the water is too hot? If so, just say so. And shouldn't that just cause cycling and not a shut down error?
Sorry about the rant but I really dislike it when Manufacturers don't understand the devices they make well enough to publish decent troubleshooting guides. It leads to a throw away society, "we don't know how it works, throw it away and buy a new one".

 

[ps0303]

Well part of the reason why it's so "cryptic" is so that not just anyone can fix it. Just like cars today, they are all computerized and so the day of the shade tree mechanic is long gone. I wouldn't have ever suggested to a customer to replace the sheet tubing but that's just me. At $1125 you're half way to a new heater. I wouldn't call is a throw away as you can break it down and sell it for scrap. Then it does get reused.

As for your error, well with so much new stuff, something is not matching up right. Are all of the parts brand new?

 

[fletchusmc]

Thanks for the interest Paul. A little background: A lightning strike fried the circuit board, transformer and ICM. The heater sat dormant for about a year until I found time to work on it. Replaced the 3 electrical parts, the heater fired up but immediately began thumping and rattling, indicating of course boiling or steaming. Removed the thermal regulator and noticed the bypass valve was broken because it hung down interfering with the R & R of the regulator. So now I have to open the manifold. Was the older design, with the cast iron adapter part between the manifold and the tube sheet. The cast iron adapter itself was almost completely clogged with what appeared to be rust and mineral deposits. I tried to clean it out (with a chisel and hammer) and replaced the broken bypass and installed a new thermal regulator. Heater fired up again but still thumped and rattled, although not as badly as before. So I decided to replace the manifold and tube sheet assuming that the deposits in the manifold were also clogging the tube sheet. So I bought the manifold conversion kit and the tube sheet, installed both including the insulation and ignitor (included with tube sheet) and fired up the heater. Now I believe that the internal flow diverter that directs the flow into the proper tubes was no longer there in the manifold allowing the water to follow the wrong path and not heat as designed. That is where I am now. Heater runs for about 30 seconds, shuts down with error 5 and SFS light. SFS tests normally, exhaust gas does not exceed 250 before shutdown. There is no boiling or steaming in the heater and water temp does not exceed 80 f by the onboard temp display.

 

[racket]

Can you post a picture of the control board and the stack flue sensor.

Unless your heater is completely sooted up it should take a few minutes to set off the stack flue sensor. There may be something else wrong. I am also concerned that you cannot access the stack flue readout. Maybe you have a really old control board that used the old stack flue switch connection, instead of the stack flue sensor.

 

[fletchusmc]

Or perhaps the board is bad? It is a revision 8 board, I think that is the latest version. I have verified it is set up for the sensor and not the switch. I tend to also suspect the board because I can't display the exhaust temp when everyone else does. However I also suspect the board runs a self-test when it powers up and would alert you to a fail state. But in the absence of adequate documentation I'm just guessing like everyone else. There must be more technical information out there for this board. For example, where does it say to hold the pool on button down to display flue temp? It's not in my manual anywhere.

 

[ps0303]

The boards do not alert you like you think. Again, the manufacturer wants trained people to work on these things. However, like most things you can usually find answers here on the net. Also though, there are times when a trained repair person would actually have to be standing in front of a unit to diagnose it.

 

[racket]

The boards do not alert you like you think. Again, the manufacturer wants trained people to work on these things. However, like most things you can usually find answers here on the net. Also though, there are times when a trained repair person would actually have to be standing in front of a unit to diagnose it.

In this case they would likely just pull a board out of their truck and test it.

Also make sure that the ribbon cable on the board to the membrane switch is lined up correctly and not broken. You can do this by testing pool on spa on and off buttons as well as make sure the up and down arrows actually work. I've seen many people not be able to get in the diagnostic mode because the ribbon cable was broken.

I have worked on hundreds of the Master temp/ max e therm heaters and don't ever recall seeing error 5 being displayed. Usually the heater shuts down with the "service heater" light illuminated with the SFS glowing as well. Maybe you problem is the control board. As long as they stay dry they are usually rock solid.

 

[fletchusmc]

Well, here is the final disposition. The control circuit board was bad. Received another new one today, installed it and everything works fine now. I appreciate the comments and suggestions, a little knowledge and experience go a long way. Keep up the great work.

Tony

 

[racket]

I had a feeling... Glad you got it working.