Bd message on heyward heater when I returned from vacation. I set it to a lower temp than usual (73 degrees) since away and didn't use for the week. Now not turning on any suggestions ?

SOURCE: temp shows 2 degrees warmer than what is was set to

sometimes the furnace does a better job than anticipated, i wouldn't worry about it, especially if the furnace shuts off.
the setpoint is the temperature you want it to be
cycle lenghts are determined by how much recovery you are requesting. for instance, in the morning when you wake up, you want the temperature to be at its setpoint. what the thermostat will do is make the furnace run a limited lengths during the recovery process.

SOURCE: We have our Sub Zero model 650 frig set to 35

Check for a fan motor in between the freezer and the fridge. Or you have a block of frost in there shutting off air flow.

SOURCE: Sta Rite Sr333na Max E Therm Pool & Spa Heater gauge stuck?

Anytime the heater is reading the water temp to be above what it actually is, especially 126, the problem is the Thermistor, or Temp Sensor, for the heater. This is a very easy part to replace. The Thermistor is located on the manifold, on the left side, between the top two bolts.

Sorry this is a late response! Hope that it helps!

SOURCE: minimax pool heater cuts out at 91 degrees when remotely set for

Check the temp reading on the heater. It is probably set at 91...heater control should be set to 104

SOURCE: Honeywell RTH2310 thermostat temp variance

Hi,
Yes you can change that by change the number of cycles per hour that your t-stat looks from for youe furnace. Lower the cycles per hour number and it will increase the range.

You can see how to do it here

http://dl.owneriq.net/3/39359643-dfda-451d-bb81-828eecddd9fc.pdf

I hope that this will help you to solve your problem!

Thanks for using Fixya!!

Heatman101