Customer Reviews

Intermatic WH21 Electric Water Heater Timer

5 star:		(33)
4 star:		(16)
3 star:		(5)
2 star:		(2)
1 star:		(6)

 

 

This product is easy to install if you know what you are doing.
You should have some background in electrical ampacity and wiring basics.

I did have to purchase an additional pigtail.(flex tubing with 3 #10 color coded wires, and 1/2 connectors on each end about 5 feet total length)

The heater had the wiring flex tubing direct from the wall to the top of the heater. The additional material was about 10.75 at the local hardware store.

I unhooked the wiring from the heater and wired it to the timer, then wired the new pigtail to where I had disconnected the original wires.

The timer has knockouts on the bottom for either 1/2 or 3/4 inch connectors so if it will accomodate either one. You most likely will have 1/2" connections.

Make sure you turn off the breaker before you start.

The entire process took about an hour total.

The instructions that come with the timer aren't that great, so if you don't know what you are doing, it won't help much.

The timer comes with 3 sets of on/off clips so you can time it on and off 3 times.

We set it at on at 5 am, off at 8 am, then on at 8 pm off at 10 pm.
So the timer is on 5 hours a day and off 19.

We figgure we will save around 25 dollars a month off the electric bill.

So... it will take at least 2 months to pay for the timer and other materials we bought. If you pay someone to install it, it will take much longer to pay for itself.

So far, it is working properly and so I am satisfied.

Having purchased 3 of these units over the years I feel qualified to comment on their performance. The first one failed after 3 years - the clock mechanism still turned but the switches did not operate. I purchased a second unit as I did not want to install a new box & wiring. The box mounts to the wall first then the mechanism is installed inside. I only replaced the mechanism. This lasted for 2 years before the clock mechanism stopped turning. (I should have kept the first dead one.) Again I purchased another unit as wanted a simple fix & I will not be in this house for much longer. This last unit only lasted 2 weeks before the switches stopped operating. I did not want the hassle of dismounting & returning it so I stripped down both units & made good one out of the 2.
The mechanism is very old school & has not changed in years. The clock mechanism becomes very hot from being driven 24 hours/day. I does not appear to be adequate to drive the system contimually. I would recommend purchasing a modern electronic system.

I purchased one of these. I have it set to turn the water heater off between 11:00 PM and 5:30 AM. I save the cost of this every month in electric savings. A worthwhile addition to a house.

Have it set for 5 to 6AM, noon to 1PM, and 5 to 6PM. Never ran out of HOT! water. Saves at least 50% of heating cost and was a snap to install. Don't understand why they don't build something like this into the Water Heater... Now there's a $$$$ making thought?

Seller shipped promptly and professionally. Item received a week before estimated date.
The timer switch works great. I have it timed to be on 3 hours in the morning and 3 hours in the evening. We have plenty of hot water. My electric bill has dropped 20%. It was well worth the purchase.

The WH21 Electric water heater switch is the best thing to happen to an electric bill, my was cut 33% and we always have hot water, but this controler will only last 12 years and we still have the same water heater
but had to replaced heater elements twice so far, to bad Intermatic did away with this model, maybe it lasted in the field too long for them.
now if only I could find something to save 33% car gas.....

Disregarding the fact that this clock was in pieces by the time I received it and never worked, upon inspection I found the wiring compartment too small to accommodate #10 solid wire, also it only kills one leg of the power on a 220 circuit. I recommend a full size clock like the WH 40 or something similar. I'm a licensed electrician in Fla.,Cal. and Ark. and I found it to be a major piece of %#*&!

Dealer fast and great to deal with. It cost so little and Item easy to install and Works well. I am a woman and installed it myself in 20 minutes or less. Cut my electric bill by more than $50. a month. I can live with that. Should have bought this a long time ago. It more than paid for itself the 1st Month. I set for 8Am to 12 pm and 4 to 6 pm and have hot water all the time. It proved to me the hot water heater doesn't have to run 24-7. Highly recommend this to anyone who doesn't have money to throw away.

I purchased this for a 55 gallon water heater with two 4500w elements.

Only one element is on at a time (normal for most water heaters)
so I could use this SPST device with a 6250W rating.

I purchased about 6' of extra 3 conductor wire (10 gauge) and screwed this to the wall. Made all the connections, set it. it works.

Most studies I could find say this does not save you much money but in our situation where our water heater is in the cold garage and we are only two people who use limited water our standby losses are therefore significant and so I think it should save us a few dollars a month perhaps.

We have it set to come on
4am-7am
4:30pm-6pm
The water is set at only 115F and is still plenty hot 2-3 hours after the timer turns off (even if one of us has taken a shower).

I recommend buying niagara conservation 1.25 or 1.5gpm showerheads "earth style" before doing this type of conservation intervention.

This timer works very well and is reliable. I purchased the first one of these units over 15 years ago.
Only 4 stars instead of 5 because the terminal strip could be a little more robust and handle larger wires.