Dayton heater troubleshoot

[rocket06]

I have a Dayton 3UF86 240v electric heater that I purchased 10+ years ago from Grainger. It has been working great but as of today it is blowing "lukewarm" air.

This model has a cluster of 3 heating elements so I'm thinking one of them has gone bad. I used a laser thermometer on each element and all were fairly close, but they are connected by a myriad of fins so that might not be a good way to identify which one is cold. The internal temperature around the fan blades etc. is about 136 degrees.

Of course I have checked all the wiring and there are no fuses in this model. A new comparable heater is $900 so I wondered if anyone has any experience or input on this type of thing.

 

[nehog]

Check the power coming in to the unit and ensure it is getting 240 volts as specified. A bad breaker might be reducing the voltage.

Check voltage at the elements and ensure each element has the correct voltage (240 volts). A thermostat may be bad, or a bad connection.

Disconnect each element and measure the resistance. If all elements are the same wattage (should be marked on the unit's diagram or specifications) they would be nearly the same.

Post the results of these tests. Be careful: voltage tests require extreme care.

 

[rocket06]

OK, now I'm really confused...

Voltage in - 235
Voltage on the heating elements- 230-235
All three elements are 17.5 to 18 ohms

I thought about the thermostat also, it is not clicking on and off ( turning off power to the elements). I let it run for a while with the meter attached and the voltage did not change. The voltage is the same 230ish on all three elements.

Maybe time to take it down for a good cleaning?

 

[nehog]

... The voltage is the same 230ish on all three elements.

Maybe time to take it down for a good cleaning?

That cleaning may be a good idea. Blow it out well with the air-compressor, clean the fan blades too.

 

[rocket06]

Cleaned it out, it wasn't real dirty, just a little dust and some bugs. Seems a little better. Thanks a lot for the help!