Intermatic WH21 Electric Water Heater Timer

by Intermatic

Product Description

From the Manufacturer

Intermatic's Electric Water Heater Timer Switch will automatically schedule hot water when needed. This time switch will repeat a preset schedule daily except when the external manual push button is used. This manual button permits the user to turn the water heater on and off ahead of the schedule. The time switch will resume the reset program by the next scheduled operation. This devise turns the water heater on during high use periods; off during low use periods. It has up to 12 on/off settings per day. The capacity is 25 amps, (6250) 250 volts, 60 Hz.

Product Description

25A, Water Heater Timer, Electric, External Switch, On/Off Indicator Light, Single Pole, Single Throw, 6,250W, 250V.

Product Details

• Product Dimensions: 7 x 5 x 3 inches
• Shipping Weight: 2.1 pounds (View shipping rates and policies)
• Shipping: This item is also available for shipping to select countries outside the U.S.
• ASIN: B00002N5FP
• California residents: Click here for Proposition 65 warning.
• Item model number: WH21
• Average Customer Review: 4.1 out of 5 stars  See all reviews (62 customer reviews)
• Amazon Best Sellers Rank: #17,518 in Home Improvement (See Top 100 in Home Improvement)

Customer Reviews

Most Helpful Customer Reviews

40 of 41 people found the following review helpful:

4.0 out of 5 stars Hot water heater timer, March 11, 2009

By 

Keith Hellwig "Helldigger" (Phx AZ) - See all my reviews
(REAL NAME)   

This review is from: Intermatic WH21 Electric Water Heater Timer (Tools & Home Improvement)

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.

27 of 27 people found the following review helpful:

2.0 out of 5 stars Strong Case - Inadequate Mechanism, February 15, 2010

By 

R. Ewan (Stafford, TX) - See all my reviews
(REAL NAME)   

Amazon Verified Purchase

This review is from: Intermatic WH21 Electric Water Heater Timer (Tools & Home Improvement)

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.

23 of 24 people found the following review helpful:

4.0 out of 5 stars Great for electric savings, November 11, 2007

By 

C. Holzwarth (Powhatan, VA USA) - See all my reviews
(REAL NAME)   

Amazon Verified Purchase

This review is from: Intermatic WH21 Electric Water Heater Timer (Tools & Home Improvement)

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.