Weird Heating Issue

[Bobman58]

It is wired for 220v. For some reason I thought even if it was wired for 220 that it might have some sort of step down transformer so it would run only 110 to the heater either way.
Ok so I will check with my multimeter. One red probe on one of the copper tabs that come off the board and go to the heater and the black probe on the other tab. If I have 220 then it's the heater. If I have less than 220 then it's probably the board. Makes sense. Thanks for being patient and imparting your expertise. That goes for everyone.

[Tman122]

It is wired for 220v. For some reason I thought even if it was wired for 220 that it might have some sort of step down transformer so it would run only 110 to the heater either way.
Ok so I will check with my multimeter. One red probe on one of the copper tabs that come off the board and go to the heater and the black probe on the other tab. If I have 220 then it's the heater. If I have less than 220 then it's probably the board. Makes sense. Thanks for being patient and imparting your expertise. That goes for everyone.

Is it wired for 110 or 220? Cause now we have a different scenerio than Doc just said. If it's wired for 110V then you have to check across the heater terminals for 110 volts. If it has 110v when it is calling for heat the element is bad. If it doesn't have it then the board is bad. 220 same except 220 across the heater terms. Resistance will verify it but no one ever does that cause it will only show the progression of failure in the element and those specs are hard to obtain for that particular heating element.

  Plus one.   And he just threw a monkey in the wrench, good catch!   Changing to 220 on a 110 conversion spa only changes the element, 2.5kw to a 5.5kw I believe and ups it to 220?   It's been awhile..

From one end of the element right there to the other side of the same element, when it is calling for heat (be careful)!!

The board can feed 220v or 110v through via the same control board depending on how it's wired (110 or 220) The heater element will except either voltage in a convertible tub. And the only change is speed of temp and recovery of the same element. Hence the 2.5kw versus 5.5. Half the energy with 110v but maybe more than twice as slow so longer draw, it's about a wash. Speed of recovery trumps any cost difference.

Check that voltage first. While the heat light is on.

[Bobman58]

Ok. I'll give it a shot. I have to reinstall the board. I'll report back.

[Bobman58]

Ok, re-installed the board, tub fired up as before, heat indicator came on( as before), checked voltage across heater contacts from the board and no voltage. Tried it with them hooked to the heater element and without. Same result.
Seems to be a bad board. Agree?

[Tman122]

Ok, re-installed the board, tub fired up as before, heat indicator came on( as before), checked voltage across heater contacts from the board and no voltage. Tried it with them hooked to the heater element and without. Same result.
Seems to be a bad board. Agree?

Yes agreed. Now is where checking resistance through the heater would come into play to verify it's function. But like I said that's a tough thing. The way I do it is to measure resistance on a new good heater and compare. But not everyone can do that.

[Bobman58]

Well I did check it before and got a resistance of 11 ohms across the element poles. The info I saw said it should be 9-10. So if that's true then it seems real close to me. And since it was not tripping the breaker I don't believe it was shorting out. As it is now I'm leaning toward buying a new board and seeing if that does it for me. I appreciate the help and I'll post back up with the results after.

[Bobman58]

First off I want to say thank you to all that helped me with my diagnosis and repairs. I saved hundreds of dollars for sure and learned a few things in the meantime. All good.
I bought a replacement circuit board and installed it yesterday. The tub was warmed up by the time I went to bed and is operating like brand new. Life is good.

Robert