Hayward H400 Heater Noise

[phipsi1237]

I moved into a rental home that we're in the process of purchasing. We have a pool with attached spa. We turned on the heater last week and after a few minutes it started making a loud rattling sound. It sounds like a bolt or something is trying to get through the system. I took the cover off to inspect the heat exchanger. It looks ok to me (not saying much). After some more testing, it sounds like the noise is coming from the header. The header is leaking between each of the bolts across the top. I ran the heater with the suction coming from only the spa and from only the pool thinking maybe it wasn't getting enough water flow from one or the other. Same results from both.

So, I know the header gasket needs replaced. Could this cause the problem?
Or, is it more likely to be the bypass flow valve inside the header. I haven't removed the header yet because I'll have to remove the gas line as well. Also, when I do remove the header, do I have to remove it from the inlet/outlet lines, or can I just leave it attached and push the heater away from it. Make sense?

There is no bypass valve on the inlet/outlet pipes.

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[phipsi1237]

Header photo

 

[phipsi1237]

Anyone home?

 

[Bama Rambler]

I'm bumping this because I don't know much about heaters, but I'd suspect something loose in the header. If it were me, I'd be tempted to remove it and take a look.

 

[swimcmp]

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

 

[phipsi1237]

Thanks. I'll try to get to it this afternoon. I did see some steam from the vent. Hopefully it's just the bypass valve. I think I can get that kit for less than $40.

 

[Jimbolo]

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.

 

[Jimbolo]

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.

 

[phipsi1237]

Pulled mine apart 2 days ago. Same thing. Bypass flow valve was torn almost in 2. Picked a kit up from a local store that said it was for models built after Sept '04. I wasn't sure about the date since the house was built in '05. I took it anyway and it worked. Two of the parts in the new kit looked as though they had been upgraded. I'll attach photos of the old parts soon.

 

[Jimbolo]

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.

 

[phipsi1237]

Hmm. Now that you showed the photos of the old and new, it looks like I might have installed the wrong one. First photo is the kit for H400 prior to 20 Sept 2004. Second photo is for after 20 Sept 2004. Third photo was what I took out. You can even see where the spring made grooves in the metal rod. I used the kit for after 2004. It seemed to fit great and the heater isn't making noises any more.

Jim,

When you insert the bypass valve into the header (into the guide), does the other side stick out past the header (where the gasket goes). Mine was flush. Also, it does appear that the new part you ordered is longer than the old. Mine were the same length. They were just made of something different and sturdier, much sturdier. The bushing thing that goes on the rod to hold the spring on was much larger and plastic. The old one was metal and a smaller diameter.

If you don't want to order the part yet, you can always call Hayward with the serial number and they'll give you the year of your unit.

 

[Jimbolo]

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.