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Your cart is empty.The Wt8840 Series Is The Water Heater Control For Trade Use to replace WV8840 valves on AO Smith water Heaters. It Is Designed For Use In Standing Pilot Applications Using An Immersion Well For Water Temperature Sensing. Made in United States. Manufactured by Honeywell.
Darren F
2025-08-25 14:52:24
I thought I needed new water heater but after some research I purchased this and it has worked perfectly for over a year now.
J. Batchelor
2025-08-18 10:40:36
Replaced Honeywell Gas Control Valve that was flashing 5 times, indicating a bad temperature sensor in the tank. The old model just had a plastic cover where the temperature sensor is located, the new one has a metal jacket over it to protect it. Just check the chart to make sure you are replacing and ordering the right part. Original Honeywell part WV8840B1041, replacement part WT8840B1000, 1" insulation tank. The new light blinks white, does not say Honeywell on the part, but looks 100% like original. I recommend threading a 4" or 8" nipple into the gas supply opening to help provide leverage when unscrewing it from the tank.Additionally, if you are getting the 5 blinking dots, indicating a bad sensor, you can fool the valve while you wait for the new one. Turn temperature knob off, disconnect either the red or white wire until the unit stops blinking. Reconnect the wire, light pilot. Once you have the one blinking light indicating a good pilot, turn temperature knob to desired heat setting. The burner will fire up and heat water to desired temperature and then the sensor will trip out again. You can do this for a day or two while you wait for your new part to be delivered.I recommend draining the tank fully, it's just easier, but takes more time. You'll need an adjustable wrench, maybe a pair of long nose pliers. And of course, pipe plumber's tape for the threads screwing into the tank and maybe some pas pipe plumber's tape (yellow) for the gas line. The total time is about an hour, most of that was waiting for the tank to empty.
mikeworldtraveler
2025-08-12 11:12:03
Same situation as others and needed a replacement. Have an AO Smith water heater about 8 years old. Honeywell controller showing five blinks indicating temperature sensor failure. The replacement took about 1 hour. I turned off the gas in the morning and started draining went I came home from work. Started taking the gas pipe apart starting at the union. That was the hardest part and I suggest using proper pipe wrenches. I used pipe dope and tested gas leaks. Nothing bubbled and no gas smell. Startup was the same. Only difference is the white light vs red in the original. Water has been staying hot and burner starting and stopping properly. There are YouTube videos that helped explain the steps you can see. Hoping this control valve lasts longer. Next is to check the anode rod again next year and drain.
Gaviota
2025-08-11 10:00:10
We have hot water! Thank you
JDuBBedition
2025-07-16 13:56:05
Will change this review to a 5 star if customer support can assure me the issue I had doesn’t happen to the next person.You should not have to open a new product. After I swapped the part out I was still getting the temperature sensor failure code 5 error.So I pull out the entire bottom of the tank clean and scrubbed every surface with wire brushes and tightened every cable up.I started to process a replacement with Amazon so I decided to try something I found in a Reddit post and swap the board out.Opened the new part and found out that a sealed new product wasn’t assembled all the way. The temperature sensor wasn’t plugged into the board.3 hours on something that should have taken 45-60 minutes…Quality control should have checked this.For everyone else reading this. If this happens to you check and make sure the temperature sensor is plugged into the board. Some people call it a thermistor.
junjun
2025-07-08 17:59:05
Direct replacement to WV8840B1109. Our old one lasted 8yrs and caused flooding on the seals of the Gas Control Valve. So far this unit looks like an upgrade with a metal jacket in the sensor. Took 30mins to swap the unit but took all day to clean the flood mess.
Joel B.
2025-07-01 16:00:54
Fit and works perfectly for my State model GS640YBRT 300 natural gas 40 gallon water heater manufactured and installed in 2011. This Honeywell WT8840B1000 replaced the original Honeywell model WV8840B1042. In 2019 mine began to leak dribbling water from the bottom of the Honeywell gas valve itself. (Bad design Honeywell! This should never happen!) Replacing mine is just like the YouTube video others mentioned by searching: Water Heater Gas Valve Replacement. See the Q & A section and other reviews. Here's my helpful tip. The larger gas line to the burner was unbelievably tight. The whole valve flexed where I though it would break off at the part that screws into the tank, even when trying to counter by pulling the gas feed pipe on the opposite side. Solution was to gently wedge in a 5/8" thick piece of wood behind the valve against the tank. In my photo I'm holding the wrench up where the line was attached (loosen by pulling the wrench toward me). Also in the photo I cut fingers off a (blue) disposable glove and put them on the pilot and burner lines to keep them clean. Second photo is old and new valve side by side. There was a crack in the plastic sensor tip responsible for the leak. Newer improved model has metal tip. I used open end or adjustable wrenches for all the fittings. Used vice grip and robo grip pliers for removing the gas feed pipes. Test for gas leaks with soapy water in a spray bottle. Not too difficult for a do-it-yourself person. I took my time working at a slow steady pace, a few hours. The YouTube and included instructions were very helpful. I'm delighted and saved hundreds. Remember to cut off the gas feed valve and drain the tank first.
Anna V.
2025-04-22 15:48:04
I got this almost a year ago and it works wonderfully! My thermolcoupler went out now so words of wisdom...buy the thermolcoupler when you get this or you might be in my situation and be buying one 10 months later 😅
Robert Nester
2025-04-18 16:47:58
Nothing to dislike. It was exactly as needed. I now have my hot water tank running. The tank itself was in great shape. I saved lots of money by just replacing this. I wish I could of just bought the control board for half the price but it wasn’t listed. The whole unit was reasonably priced and again very happy to have hot water again.
Leanne
2025-02-22 17:24:27
The item was exactly what I needed. If I had an American type of water tank!!Oh I was so disappointed!!!! Can’t they all be universal!Item was in perfect new shape. The shipping only took 4 days!!!!!!This is the first time I have ever had to return anything. So we will see.So far seller was excellent!!!UPDATE: my refund was returned.With everything I experienced with this seller, if given the opportunity, I would definitely buy again
Ben Ballano
2025-02-11 16:20:09
It works well with my hot water tank, thank you very much.
AndyDandy
2025-02-01 12:17:52
Product was damaged on arrival
Wayne L.
2024-12-08 18:39:06
Ad said it was prefect replacement. Yes it was ok till hooked up burner tube. Had to cut 1†off and reflare end of tube. Special tool required
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