Hayward H400 Heater Noise

Make sure you have plenty of flow, a heater can "boil" water in the heat exchanger if you don't get enough flow

I have the same heater, and this weekend after heating all day Saturday, it started making the same noise on Sunday. Mine sounds distinctly like boiling and the resulting gas popping. it shakes the plumbing down-stream from it. I downloaded the manual for it and it said that the bypass valve can get stuck if minerals are high. When I moved into the house two years ago, calcium hardness was off the charts.

So I'll pull it apart this weekend and see what I can see. I'll report back.

Jim.

So I pulled the heater apart yesterday. The bypass valve insert had snapped. It's a plastic paddle looking thing. Getting to it was pretty straight forward, although the coupling rings were very tight and bigger than my biggest pair of channel locks. That took some work. Strap wrench wouldn't work either. Finally got them loose by getting as much bite with my channel locks as I could, then having a friend tap them with a hammer while I kept the pressure on.

So today I'll order the insert and a new thermostat. Might as well replace it while I'm in there.

Jim.

Well I opened the box today with the intention of replacing the bypass valve insert. Unfortunately the new one does not fit. There's a part on it (marked "valve guide" on the photo) that has to slide into a groove on the inside of the header. But when I do that, the end opposite the thermostat (left side of the picture) runs right into one the copper outlets from the heat exchanger. I cannot remount the header with the new bypass insert. It won't mount flush. Photo attached. There are only two parts available as replacements: HAXBPK1931 and HAXBPK1932. I have 1931 now. 1932 looks different, but without dimensions I can't tell if that one will work or not. Plus the valve is different in the kit, meaning the retainer on the insert is probably different too.

Anyone have any ideas? I emailed Hayward, but I have no idea of how helpful or responsive they are.

Thanks, Jim.

Hey Phipsi, the parts you took out of yours in your photo match the 1931. So did mine. The parts you put back in match the 1932. If it works, it works. My old parts exhibited the same wearing that you describe, and the metal tube that attaches to the valve (round part at the end of the spring) was worn and broken away.

To answer your question, the new part appears longer only because of the shadow and photo angle; the length of the section I call "valve guide" in my photo is the same on the old and new. When I slid the insert into the header, it did not protrude past the edge with the o-ring. Problem is that the brass pipes that protrude from the heat exchanger (that the header mounts up to) protrude into the header when it's mounted flush. And one of the pipes aligns with the section that I labeled "valve guide" on my picture. It's that alignment that will not allow the header to mount flush. That part should meet the exchanger such that it goes between the protruding pipes, as the old one did.

Thanks a ton for the dialog. It's been a really sanity check for me to make sure I'm not too far off base. I contacted the people I got the kit from and I'll see if they'll exchange it for the 1932 that you installed. Like I said, if it works, it works. From the looks of my burner after I pulled the cover off, I won't have that heater in 2 years anyway.

Jim.