H-Series Natural Gas Pool Heater for Inground Pools 400,000 BTU | W3H400FDN Universal H Series Swimming Pool Water Heaters feature High Quality Cupo Nickel Heat Exchanger w/ Low NOx Emissions

Easy to install. Not cheap, but efficient heater for my large pool. It has been 2yrs, and aside from the mice that ate the wiring harness to the display, it was worked great (display was easy to replace and parts are easily accessible which is also nice to make sure this lasts for a long time to come. I think the wires may have been soy based insulation which may be part of the problem). Otherwise it fit where my prior unit was as I just replaced the 20+ year old unit. Not the quietest of devices, but as this is my first pool/hot tub...not sure if they get quieter.

So I purchased nearly identical model 17 years ago. Self installed except for need of larger supply line for gas input that required a licensed plumber. While I did have a couple failures related to the odd geckos crawling up behind a circuit board with 220 voltage (part easily obtained from Amazon and replaced myself) and shorting out. The heater performed wonderfully! Fast forward to this spring and it was not working after winter months. No input from control board. Tested things I was sure of to no avail. BUT then realized this was 17 years old! I purchased this newer version and it arrived. Unwired and unplumbed from old and connections identical to new. Rewired and replumbed in about 45 minutes and it was up and running 100%. Highly Recommend Hayward products. I also use there pool pumps and sand filters among other odds and ends. Always satisfied!

Have had this heater for three seasons. Only need to use it for a few weeks per year at the beginning and end of summer. It hasn’t run constantly during that time but mostly when the kids wanted to swim and water was cool. Went to start up go this season and unit will not work. Dan comes on but nothing else. Had a pool company come check it out then they called Hayward for parts and was told that the unit was discontinued and there’s no parts available. I was shocked and find this completely unacceptable especially considering the cost, time from date of purchase and that this is supposed to be a reputable company. I would absolutely consider another brand.

Heater works great had a 200,000 Hayward prior to this and a 20,000 gallon inground pool the 200,000 struggled to keep up and eventually stopped working so I decided to go big with the 400 great move because it pretty much slipped right into the same fittings that the 200 had the only thing I had to change was my gas and that was minimal Had it up and running in a couple hours and heated the pool 20° overnight. The shipping was excellent R & L carriers delivered it. It showed up without a mark on it. It was a few days late, so I was mad about that but other than being a few days late I definitely go back to that company again they did a great job shipping it

Driver drop off heater without ringing doorbell wonder why? Cosmetics damage- How would feel receiving a new car with a dent on the fender? Hopefully the heater operation will work. I am waiting for the installer.

So glad I tripped the trigger on this. I went with 'go big, or go home'. I'm only heating a 15,000, but when I want to heat it up for visitors, we live in S. FL we get many, I don't want to have to start days before like I did with a heat pump. And if the weather was cooler, yes it does happen in S. FL, it would take a heat pump forever bypassing the timer and running it 24/7. This brings the pool up three degrees an hour. And with a lightweight cover this can't be beat. And when the visitors want to use the spa it's up to temp in minutes, not hours. If you're just not sure about gas vs. heat pump, take my word for it, this is where you want to be. You don't need to run it as long to get to, and maintain where, you want to be. You could run this thing in the dead of winter no matter where you are. Good luck trying that with a heat pump.

Bought this to replace an old broken rusted out Hayward H400IDL that was about 15 years old. My old heater seemed to breakdown every 3 months or so. I’m hoping this one will be more reliable. The installation wasn’t to bad I did it myself but the biggest negative was when I called Hayward and they told me the H400FDN was an exact replacement that wouldn’t need plumbing adjustments to fit but that wasn’t the case both the water and gas connections had to be reworked to line up. Nothing to difficult but it required a trip to Lowe’s to get everything working. Overall it seems like a good heater although it doesn’t look like the picture shown on amazon? the control panel is completely different then what is shown. Also don’t forget to register online for your warranty and apply for a rebate with your local gas company I got an extra $300 off with a rebate from SoCalGas.

Delivery was good and install was fairly easy. Make sure the gas company gets the manual and reads it for the size correct line. Unfortunately, ours had to redo it but they fixed it with no problem. Since things got delayed and it is warm now, we started it but have not actually heated to pool. I dont know why but it is much larger than I was expecting. The box was even larger.

Pool heater,