20 Most Recent Electric Intermatic Inc Wh21 Water Heater Timer Single Questions & Answers

There is a short. The timer mechanism is mechanical, so the problem is not failed electronics.
The WH21 is for 240 volt circuits, so it has 2 hot wires and 1 ground from the breaker box. Only one hot line to the water heater is turned off, but both lines are attached to screw terminals at timer.
To see if the problem is a shorted element or shorted wire in water heater, disconnect hot leads to water heater one at a time, and then test. Then disconnect ground wire from water heater and test again. Then disconnect all wires to water heater, and test again.
If the problem is in the water heater, search for troubleshooting steps on internet. Focus on testing elements.
If the problem is not in the water heater, then a frayed wire on back of timer is next checkpoint. The timer motor is the final suspect. You can detach the timer motor from the housing, and test for stray voltage. Intermatic WH21 is inexpensive to replace.

Lost the manual ? then google for it. turn the dial to 6

defective unit. get a new one.

https://www.hunterindustries.com/en-metric/support/why-does-my-controller-display-no-or-no-ac

This ought to be a Harbor Freight product (#40148) and here is their manual for it: https://manuals.harborfreight.com/manuals/40000-40999/40148.pdf Rotate the dial, clockwise only, until the time printed on the dial lines up with the arrow.

That means it has reached pressure; reset it and use it.

Sounds like an outdoor dawn-dusk timer: Manuals for several types and brands appear on following link: http://waterheatertimer.org/Outdoor-timers.html#digital If you need further help, I’m available over the phone at https://www.6ya.com/expert/gene_9f0ef4df2f9897e7

The power going into the timer will be black, (Hot), and White(Neutral) using a multitester set to AC voltage 600v, will give you the voltage. Be careful when working with Live electricity.

There should be a fuse or breaker that would turn that off. It should be on one circuit by its self for the bathroom heating system. If its a breaker just flip the breaker switch.

Probably need contactor for any pump rated 1Hp or more. Wiring shown on following link: http://waterheatertimer.org/How-to-wire-DTD-1440-timer.html#SUL Gene Water Heater Timers Save Money If you need further help, I’m available over the phone at https://www.6ya.com/expert/gene_9f0ef4df2f9897e7