I have a Mastertemp 400 heater, less than 5 years old. When I heat my spa, the heater comes on, then the burners ignite. They run for about 45 seconds, then they shut down for 30 seconds, then fire up again. Cycle continues until spa reaches desired temp (very slow). There are no error codes, and I confirmed my variable speed pump is running at 50gpm, higher than the listed minimum 40. Is this normal?
Heater Cycling
- Thread starter Bbanerdt
- Start date
- Jul 21, 2013
- 52,817
- Pool Size
- 35000
- Surface
- Plaster
- Chlorine
- Salt Water Generator
- SWG Type
- Pentair Intellichlor IC-60
Welcome to TFP.
Short cycling is not normal.
Check the thermal regulator.
If not the thermal regulator check the internal bypass valve.
Check the stack flue temperature.
www.troublefreepool.com
While running, press and hold the On button to display the exhaust temperature (Older Models).
The new models use the Menu to get the SFS.
Here is what the normal exhaust temperature should be:
If the exhaust gas temperature is higher then normal then water may be bypassing the heat exchanger through a broken bypass valve.
If you hold down the "pool on" button, it stays on 80, then flashes to 40, then back to 80, then the 80/40 reading and E05 indicate that the board is not getting a reading from the sensor. It's usually a bad sensor or damaged wires.
Short cycling is not normal.
Check the thermal regulator.
If not the thermal regulator check the internal bypass valve.
Check the stack flue temperature.
Pentair MasterTemp Heaters - Further Reading
www.troublefreepool.com
While running, press and hold the On button to display the exhaust temperature (Older Models).
The new models use the Menu to get the SFS.
Here is what the normal exhaust temperature should be:
- Below 250 degrees...very low
- 250 to 290 ..................low
- 290 to 350.................acceptable
- 350 to 480 ..................high
- Above 480...................error/shutdown.
If the exhaust gas temperature is higher then normal then water may be bypassing the heat exchanger through a broken bypass valve.
If you hold down the "pool on" button, it stays on 80, then flashes to 40, then back to 80, then the 80/40 reading and E05 indicate that the board is not getting a reading from the sensor. It's usually a bad sensor or damaged wires.
If you look on the back of the control board, one of the error LEDs may light up when the heater shuts off. If not, you may need to install a new ground path (wire) for the flame sense circuit. Pentair makes a kit, P/N 475214Z. The instructions are attached. You can use a piece of green wire (to indicate it is a ground) instead of buying the kit. Just be sure the areas where the wire is attached are clear of any rust or corrosion (not un-expected after 5 years of use). This is the easier than removing the control and won't hurt anything if you just go ahead and try it first.