Aquasmart 7610B Temperature reading

TerrS

Just had the above installed and we are seeing a 15-20 degree discrepancy between the boiler temperature gauge and the Aquasmart. The aquasmart is reading higher which is causing the boiler to shutoff sooner. Its not an issue yet as the house warms up, so it is supplying heat. Has anyone else seen this issue?

I could see if it was reversed maybe the placement of the sensor was not against the well correctly or something like that, but not with it reading higher.

Any thoughts? Defective sensor maybe?

Robert O'Brien

This is common due to the stacking effect and residual heat from chamber/refractory after shutdown. I assume you're comparing the digital reading to the tridicator gauge? Tridicators are inaccurate and not installed in same location as Aquasmart sensor. Nothing to worry about.

TerrS

Thanks, I just know when I had my old Honeywell aquastat installed I would see the boiler cut-off around 180-185 degrees. So I was trying to compare the two. Do you recommend leaving my high limit at 180, or changing to 195 or 200 to account for this?

I dont want to over temp my boiler, but since I have slant-fins, they tend to radiate heat better around 170-185 degree water.

EdTheHeaterMan

There will always be a difference in the reading between 2 different type of measuring devices located at different points on a heating system. One of the gauges may be out of calibration, Or both may be out of calibration in opposite directions. There may also be a temperature difference in the locations of the actual sensors.

You do not need to compensate for the difference. if the system operates as expected then everything is fine. Actually the lower the temperature settings are, the less fuel you will use. If the temperature is too low you will find the heating system will not provide sufficient heat on the very cold days. SO... If you have enough heat (and hot water if your burner provides both) then you are all set.

The only adjustments that are necessary are those needed to correct a problem. if you have no problem, no adjustment needed.

ryan242

Mine does the same thing except in the opposite direction, my aqua smart reads about 5-10 degrees lower than the Tridicator, I trust the aquasmart over the tridicator though, especially since mine is over 20 years old

HVACNUT

The High limit is set to 180° and the boiler is actually making 180° even though the Heat Manager is economizing? Unless your at design day temperatures, the boiler shouldn't get to 180° The display should show the adjusted "economizing" setpoint. The differential stays the same.
I would lower the High limit to 160° and see if the zone(s) maintain temperature. If not, I would raise it in 5° increments. 
All this is moot if the boiler has a tankless coil. Then you just have a glorified triple aquastat. 

TerrS

This boiler setup is pretty simple, no dhwp with 1 zone/pump.  Until this morning the high limit dynamic was around 174 degrees. Today it's cold and aquasmart kept 180 degrees for about 20 minutes cycling. But depending on which you trust, boiler Guage or aquasmart, the internal water temp seems to be around 15 degrees less. I know with the original Honeywell aquastat I saw the boiler Guage always at 185. And shutoff. So this is why I am questioning.

Now if I wanted to spend $7k on a new 95% efficient boiler, I would probably resolve spending less in natural gas.