Hello all- Long time lurker and now first time poster. I'm hoping someone with knowledge of these blower motors can help confirm my diagnosis of a bad motor or point out anything I may have missed.
I have an early 2003 Hayward H400IDL (not v2) and this unit has had little use over it's life- it is virtually new a far as actual use goes and it has been in a protected location in the desert. no rust etc. The previous homeowner installed it back in 2004 and never got it to work, I don;t know why. I ended up finding out the gas meter was way too small for the home and was not providing enough gas volume to the heater. I upgraded the gas meter and have had the heater operational and working fine until this past weekend. Heater just shut down and would not re-ignite. Would flash error AO after the initial purge period.
I opened up the unit to inspect the blower & vacuum switches, motor and control board according to the Hayward service manual and troubleshooting matrix.
Switches checked out ok. Control board checked out ok. Motor resistance checked out ok.
What happens is, when the unit starts up at call for heat the blower motor is spinning very slowly- about 1/3rd of it's normal operational speed (normally that blower motor is cranking like a jet engine!). There are no obstructions on the motor or squirrel cage. the motor and cage are spinning freely and smoothly, just very slowly- like it is stuck on a permanent very low speed setting.
So because of this the vacuum switch never engages and the heater does not attempt to ignite. The motor also gets very warm very fast.
I verified this by intentionally closing the vacuum switch circuit and the heater will then ignite and fire normally.
I tested voltage at the blower motor when powered up on call for heat and is on the pre-purge cycle - Motor white to red reads 220v. Motor white to black reads 110v
I tested resistance on the blower motor windings between white / red and white / black, and all were in spec
I tested voltage at transformer and it is putting out 26v AC
Checked all wiring connections and all are fine
I tested relay circuit at control board between L1 and IND LO. the relay is switching normally.
Vacuum and blower switches functional / normal.
Basically everything obvious checked out ok and the entire unit seems to be working with exception of the blower motor turning slow- but not from any obstruction. The only thing I'm thinking is the capacitors in the motor are bad and that is why it's spinning slowly- so I need to replace the motor to fix issue.
Does that sound correct as a diagnosis or am I missing something? I'm not sure if I'm supposed to be reading 220v at the motor on both white to red and also white to black. I get 220v white to red and 110v white to black at the motor.
It is Comair Rotron motor dated July 2003, Model A138-E03HJ, Part number 562015, 206-230v, 3200/3400 rpm
Thanks in advance if anyone can help.