

🔥 Upgrade your water heater’s heart with precision and power! 🔥
The Honeywell WT8840B1000 gas control valve is a professional-grade replacement part designed for AO Smith and similar water heaters. Featuring a 160°F max temperature setting, 1/2 inch NPT inlet/outlet fittings, and a 5 psi pressure regulator, it ensures precise and reliable gas flow control. Its integrated NTC temperature sensor enhances safety by monitoring water temps up to 221°F. Crafted from durable metal and made in the USA, this valve is engineered for easy upright mounting and long-term trade use.
| ASIN | B06XNSV2BG |
| Best Sellers Rank | #43,770 in Tools & Home Improvement ( See Top 100 in Tools & Home Improvement ) #47 in Water Heater Replacement Parts #7,338 in Parts & Accessories |
| Brand | Honeywell |
| Date First Available | March 15, 2017 |
| Department | unisex-adult |
| Exterior Finish | Brass" or "Stainless Steel |
| Global Trade Identification Number | 00085267605038 |
| Inlet Connection Type | National Pipe Tapered |
| Is Discontinued By Manufacturer | No |
| Item Weight | 2.2 pounds |
| Item dimensions L x W x H | 8 x 6 x 6 inches |
| Item model number | WT8840B1000 |
| Manufacturer | Honeywell |
| Material | Metal |
| Maximum Operating Pressure | 5 Pound per Square Inch |
| Number of Ports | 2 |
| Outlet Connection Size | 0.5 Inches |
| Outlet Connection Type | Flare |
| Product Dimensions | 8 x 6 x 6 inches |
| Specification Met | Yes, meets relevant industry standards for gas control valves in water heaters |
| UPC | 085267605038 |
C**E
Worked great
Like new, dropped right in, worked like a charm. Late delivery, but recommend.
J**.
Perfect replacement for WV8840B1042
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.
M**R
Good replacement
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.
B**D
Exact match
Perfect fit. Plug and play. Hot water again !
J**N
Direct swap for the WV8840B1042 worked.!
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.
E**R
Good replacement
This water heater gas control valve works as expected and is an exact replacement for the OEM. It's easy to install and easy to configure.
J**W
Quality product
This product was identical to mine,unfortunately this wasn't the problem it was the tank itself cracked.
P**.
It works and I have hot water again!
For the record, I am not being compensated in any way for this review. I'm just happy to have hot water again after more than a week of cold showers, and want to pay forward my gratitude. This unit (Honeywell WT8840B1000) replaced my old WV8840B1042, which was throwing a "5 flash" code (Temperature sensor failure). The water heater is a 40 Gallon Whirlpool N40T121-403. Using a YouTube video titled "Water Heater Gas Valve Replacement", I was able to install this unit by myself in about 90 minutes. Difficulty level 4 on a scale of 1-10 (10 being most difficult) for a person with moderate familiarity with water heaters. Kudos to Amazon and the U.S. Postal Service. This unit arrived TWO days ahead of predicted delivery. (perhaps they know that people who buy items like this are typically in a bit of a jam? We sure were. We'd been through a week of cold showers.) I write this just a couple hours after installation and am very happy. The unit works perfectly, and MUCH cheaper than buying a whole new water heater. We have hot water again! A warm shower... one of those things you don't appreciate until you CAN'T have one. PHOTO: The new unit after installation. The old unit sits beneath.
J**D
item worked perfectly. Just after installing it the plumbers told me I needed a new tank so it was only used for two weeks. Will have a spare incase the new valve gives me issues
R**R
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.
L**E
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
B**O
It works well with my hot water tank, thank you very much.
A**Y
Product was damaged on arrival
Trustpilot
1 month ago
1 month ago