Overheat blue fail

toni

Can anyone fill me in on why “overheat blue fail” showed up on the Alde heating system?  I have had to deal with “gas failure” a lot, with inconsistent results but this is the first time for the “overheat blue fail”.  The heating system seems to be very touchy.  Any insights on how to deal with and correct these two messages would be much appreciated.

Grumpy_G

Straight from Alde:

What is "Overheat blue fail"?

This error can occur if the boiler is running at high effect while there are air pockets in the system.

    Bleed the system thoroughly, see user´s  manual.
    Check that the fluid level in the expansion tank is at least 1 cm over the min-line when the fluid is cold.

This can also occur if the circulation pump is broken or disconnected from the boiler.

To reset the error,

    The glycol temperature must drop below 41°F  (50 °C)
    Break and reconnect 12 V to the boiler.

If the error persists, contact Alde Service Partner.

Check that the circulation pump is running (put your finger on it). The bleeding procedures vary between models and years so I can't comment on that.

pthomas745

The first thing to do is reset the Alde panel so the error clears.  This can be done easily by turning the Alde off and removing the power from the trailer, and then turning off the battery disconnect.  (Or, if not on shore power, just turning off the battery disconnect switch.) This resets the error, and allows you to "try again" with the Alde.

The "Overheat Red Fail" error is much more common, and the "Blue Fail" is rarely seen, at least reports are rare.

In the Alde Service manual, which we have the "UK version", basically says the Blue Fail and the Red Fail (which they call "O Heat 1 and O Heat 2"....are basically the same error, caused by an indication of high temperatures reaching the Alde sensors on the boiler. The claim is the sensors have somehow sensed a temperature of 212F, which..sounds a little far fetched.  The other reasons, such as shorts or the "sensor has been damaged" probably are a little closer to the truth, but there is no way to verify any of it. 

The "air in the heating system" is what Alde always falls back on, telling owners to "bleed the air in the system and then rock the trailer up and down" and have the air move to the top of the glycol setup, which should be the expansion tank.  Someone on the Cirrus boards the other day complained that is what Alde told him to do...but they had no idea how he was supposed to "rock" a truck camper up and down. In my 2017, getting to the bleed valve would involve taking the whole back shelf of the trailer out...which isn't going to happen.

If your errors continue after you reset with the battery disconnect, the issue could be a bad circuit board.  I do not know if anyone has ever found or replaced the "red" or "blue" sensor.

Gas failures are a more common issue, and can be caused by several things.  You don't say what year your trailer is, but the items in the trailer like the propane pigtail and propane regulator may need to be replaced.  A technician could measure your "propane pressure" to see that it is correct.  The Alde can also throw out gas failure errors if the exhaust fan inside the Alde is failing, since the Alde checks the fan speed at startup. I've included the "Gas Out" explanations from the Service manual below. 

So, for the Gas Failure, tell us what year your trailer is, and have you ever replaced your pigtail and regulator? We can also help with the "air in the heating system" with the bleed valves.

 

O HEAT 1

Caused by:
The blue sensor on the boiler body has registered a tempera-
ture in excess of 100ºC, or break/short circuit.
Probable reasons for the fault:
• Air in the heating system.
• Insufficient circulation or pump not working.
• The sensor has been damaged.
• The electronics are not monitoring the temperature.
OHEAT
Caused by:
The red sensor on the boiler body has registered a tempera-
ture in excess of 100ºC, or break/short circuit.
Probable reasons for the fault:
• See OHEAT 1

GAS OUT
Caused by:
The heater has attempted to light the boiler repeatedly, without
the electronics receiving the signal from the sensor that moni-
tors the flame.
Probable reasons for the fault:
• No gas supply or insufficient gas supply in the vehicle.
• The electronics do not send a signal to the gas valve.
• The gas valve does not open.
• Impurities in the heater’s gas pipes or nozzle.
• No spark from the electronics.
• The spark electrode has been damaged or is incorrectly
mounted.
• The sensor circuit in the electronics is not working.
• The sensor has been damaged or is incorrectly mounted.
• The exhaust/intake hoses have been damaged or are incor-
rectly mounted.
• Insufficient battery voltage or contact fault in cable.
• Break/short circuit in sensor no. 2 (red cable).

toni

Thank you for your help to this point.  Our trailer is a 2017 T@B, Q Max 300 series, I think 320.  BTW where are the bleed valves?

pthomas745

If your trailer is like my 2017, the Alde was installed with no thought at all about maintaining the system.  The Alde tank is hard to access.  My 2017 bleed valve is on the passenger side, behind the bed, under the back shelf.  Impossible to reach, and if you can reach it, now there isn't enough room to see the valve. This photo is my 2017, with the little "triangle" on the side of the back shelf removed.  The bleed valve is under the back shelf on the floor of the trailer, and you can see it with the triangle removed.  But, no way to reach it unless.....you take the whole back shelf off.  That little gap on the left of the shelf, down about 3 feet.

If you take the bed cushions off and you can follow the hoses for the Alde back into that corner, you "might" be able to reach the valve that way. The Tab Yoga involved would be extensive.

Full confession: I recently cleaned my convectors and actually took all these things apart.  I chose to simply not put the "bleed valve" back into the trailer, and replaced it with another  90 degree elbow.  It would seem (to me) the best way to "remove the air bubbles" would be to run the pump continuously for a few minutes. 

toni

Wow!  Unbelievable that it was constructed in such a way.  Our glycol fill is on the right side similar location.  We have been able to view it and it has been refilled when needed.  We will have to see about the rest, as far as following the line to the bleed valve when we get a chance.  I have to say the blush on the rose of our TAB is beginning to fade.  

pthomas745

Except for having to remove the shelf, and how weirdly inconvenient the bleed valve was, I just had to take it in stride.  My trailer and the Alde has always worked fine.  I just had to deal with these challenging workarounds, and with the help of this group, I was able to do it.