Triangle Tube Indirect Tank: DWH Sensor Shorted...

Javelin

Heating Pros, Just put in a warranty replacement of a TT Smart 40 Indirect tank. After filling everything up, I turned it on, and the boiler shows "DHW Sensor Shorted".. I've inspected/tightened the only TWO wires that go into the sensor area on the tank.. I even looked at the factory side of things, but all looks good/tight there. Any thoughts? Could it be a bad sensor? Is there a way to run this without the sensor from the boiler, just using the thermostat in the tank itself? or is that a bad idea? THANK YOU!

Shane_2

Are you using the built in thermostat on the Smart 40 or are you using the DHW sensor that may have come with the Prestige?

I would check the Parameter settings on the boiler before anything else. If it is a TRiMax, check pages 48-49 of the manual, the last couple I did came with the PSRKIT22 sensor.

Robert O'Brien

Shane is correct, although both the sensor and mechanical temp control are frequently damaged by water when the tank leaks

Javelin

Hmm. so now I'm confused. I put the original tank in with a prestige solo 250, but now that you mention it, I kind of do remember pulling the sensor that came with the TANK out and putting in a new sensor (that I guess came with boiler?) That's what you're saying... right?

The sensor bulb/wire that came with the tank is not to be used usually then? Does that differ from the PSRKIT22 above? If I buy a PSRKIT22 sensor that came with the boiler, will that solve the short issue would you think?

Thanks,

Jay

SWEI

The SMART tanks come with an aquastat. The boilers come with a PSRKIT22 (at least since 2011 or so.)

Javelin

Thanks SWEI, So I changed the boiler to use "switch" instead of "sensor" for now and it seems to be firing correctly, I'm guessing controlled (albeit maybe poorly) from the thermostat knob on the top of the tank.. right?

I guess I should order another PSRKIT22 Sensor so that the boiler knows the exact tank temperature and can modulate better.. That's ideal right?

Jean-David Beyer

I put a W-M indirect that is the same as a TT-Smart 40 along with a new W-M Mod-Com.

After about five years, I noticed a strange sound from my garage, where my boiler and indirect are. I went to look and the P-T valve on the indirect was running (hard, not a dribble) onto the garage floor. The indirect was calling for heat and my boiler supplies almost 80,000 BTU/hour. I unplugged the aquastat from the boiler and let the thing cool down. Eventually, the P-T valve closed. I got my heating pro in and he tested the aquastat. No matter where he set it, it called for heat. So he replaced it.

The differential on the thing is about 20F, which i do not consider small. But my Caleffi thermo-mixer valve holds the temperature very tight, provided I run at least 0.5 gallons per minute.

Zman

Javelin said:

Thanks SWEI, So I changed the boiler to use "switch" instead of "sensor" for now and it seems to be firing correctly, I'm guessing controlled (albeit maybe poorly) from the thermostat knob on the top of the tank.. right?

I guess I should order another PSRKIT22 Sensor so that the boiler knows the exact tank temperature and can modulate better.. That's ideal right?

You got it. That is exactly what happened.
If you still have the old tank you could pull the sensor out. Not a bad idea to put in new anyway...