tarm temp. probe question?

[woodmeister]

have just got tarm up and running but the temp gauge on the control panel isn't close to the aquastat thats measuring the water temp. at rear of unit ( controls circulator upstream of termavor valve ) control panel temp gauge reads 190 aquastat reads 140 fire is stoked down but the unit won't allow you switch the fan on. Could it be a false reading on the control panel temp. gauge?

 

[oilbegone]

One setting that I had to check a couple of times (I had it wrong at first) the low limit thermostat on the back of the control panel has a scale that is in Celsius. If you have that set thinking the knob is in Fahrenheit the probe in the smoke box thinks the boiler is cooling down. Check to see that you have that set at 60 C (for my solo 30) or whatever yours is supposed to be set at in C not F.

 

[woodmeister]

oilb, that setting is correct

 

[oilbegone]

Sorry I could not help. I have only had a few fires so far and am not yet familiar with all the ins and outs. I hope someone comes up with the solution to your problem. Think I'll get an IR thermometer and a moisture meter to aid in monitoring the process.

 

[Gene C]

have just got tarm up and running but the temp gauge on the control panel isn't close to the aquastat thats measuring the water temp. at rear of unit ( controls circulator upstream of termavor valve ) control panel temp gauge reads 190 aquastat reads 140 fire is stoked down but the unit won't allow you switch the fan on. Could it be a false reading on the control panel temp. gauge?

The 190 degree reading on the front control panel is the actual water temp in the boiler.(Its measured midway back on the top of the boiler) The safety system won't let you turn on the blower because you are already at the upper limit. I think that what you are seeing is that the aquastat at the rear of the boiler is not seeing the 140 degree temp water it needs to turn on the circulator pump to get the water flowing. The aquastat is mounted in the output pipe in a tee? The nipple you used may be too long and keeping the temp probe too far from the heat to initally turn on the pump. (That was part of my problem!!) However, I decided to take the easyway out and used the "PUMP" switch on the control panel (it is there but not normally used in the Tarm installation instructions) to initally power up my circulator pump to force hot boiler water past the aquastat probe and trigger its operation. I wired the switch into the aquastat for the circulator. Once the aquastat itself has activated the pump, you can shutoff the manual switch on the Control Panel and let the system run automatically. Your blower will come on when the water temp calls for heat.

 

[twitch]

Gene C
I just finished piping all the black iron and supply / return manifolds on my Tarm 30. How far from the supply out of the boiler up to the aquastat would you say is too far?

 

[Gene C]

My aquastat well was approx. 3" from the flow of water in the tee. Once the well was located at the edge of the water flow in the tee everything worked well. Remember, convection needs to have a chance to work. Without rise in the piping, the hot boiler water doesn't get to the aquastat sensor probe quick enough to turn on the pump before the boiler upper temp limit shuts down the blower. (Initial startup)
I still like the idea of wiring the switch on the control panel into the aquastat to initally turn on the pump. I haven't figured out why Tarm installs the switch but doesn't call for it in the installation process. Maybe I need to read the manual again!

 

[chuck172]

Gene, the wiring on the front panel have numbered lugs. What numbers did you use for the pump switch?

 

[Gene C]

Presently not close to boiler. Will PM when I return.