I have A hayward heater H100IDEVERYTIME the heater kicks on it makes A clunking noise and the inlet hose shakes

What do you mean by clunking noise, a single hard bang or like popcorn popping around inside? Right position an what part exactly, what is loose, baffles on top of the exchanger? What model heater?

is this heater is been install for above the ground pool it will be better either way to use a hard schedulle 40 pvc to prevent any checking in the hoses for future leak ,is the heater connections are correct in and out , mean from the return the filter go to inlet side the heater them the outlet side of the heter (HOT WATER) GO TO RETURNS of the pool ? also check if the pump got full prime not air,is the filter is clean? also check for any brocken parts inside the flowvalve control, after years low PH AND TA will destroy internal parts in heater include leaking heater exchangers.

Thank you for posting your question here on Fixya.com.

The Hayward H100 has a diverter plate welded into the header that helps direct some of the water flowing thru into the heat exchanger to heat the water. If the weld fails the diverter can interfere with that flow and cause overheating or poor flow thru the heater which in turn can lead to the problems you describe.

Remove the inlet side hose once you have blocked the flow of water from the pool and you should see the diverter in the inlet. If you can move it then it is broken and needs to be fixed back in place or the whole heat exchanger needs to be replaced.

If the diverter is not moving then your issue is likely an overall water flow one and the next place to look is the filter. Poor overall system flow may be enough to close the pressure switch telling the heater the pump is on but not enough to keep the water in the exchanger from getting too hot, again causing the symptoms you describe.

If this answer does not fix your problem, please comment with additional details prior to rating the answer. You may also contact me thru our website at www.arrowpools.net. Positive feedback is appreciated once your problem is solved!

John

Is it leaking? Has anything shaken loose inside? If you can get it to light the cause and fix for the banging and shaking is here: https://sites.google.com/site/haywardpoolheater/
Takes about 30 minute and you are done, but you have to figure out what else has gone wrong to stop it lighting

This is a by-pass problem ether internal or external. Internal is a project and you may want to get some one fimallar with your heater to help. If it is the external this is just a valve bridging the inlet and outlet pipes. Just close this down most of the way and force the water to go through the heater. with it open it gives the heater all the pressure it needs to start but you have water pushing down the inlet and outlet pipes so it can't go anywhere. The water inside the heater overheats and turns to steam giving you the banging and shakeing you have. Good luck.

Check to be sure your heater by-pass is closed off. If not the water inside will overheat and shake and bang inside the heater.

That plate should not move at all. If it is moving is is damaged. In the past that meant replacing the heat exchanger but I recently had someone tell me they took theirs to a radiator shop that tach welded the plate in place and it works fine now. Either way, the rattle is from water boiling in the unit due to poor flow through the heat excahnger. The plate we are talking about is what controls that flow.

I had this problem with mine ( hayward h series abg100 ): exhaust fan turned on, waited approx 15sec, gas turned on, ignition, flame lit (can verify in flame window below knob), stayed lit for ~5-10 seconds (varied), I heard popping, cracking, knocking, banging noises, then gas turned off.

I believe the reason it does this is the bypass/diverter plate in the exchanger (right at the inlet side) is loose; the weld broke loose. They weld this very poorly and is obviously a known issue with the unit. I think storing it outside in the winter doesnt help. Another reason for the noise could be not enough water going through the exchanger because of a problem with the diverter plate, therefore the exchange gets to hot and boils.

I believe the ignition board senses this somehow (not sure how though, only way I can think of is via the ignition sensor), and cuts off the gas. I managed to fix this by putting on a small stainless steel hose clamp around the thermostat forcing the divertor plate tight up against the top so the water flows through the 3 exchange pipes. This was a very difficult maneuver due to working inside the tight pipe, but it worked!

You can check if you have the same problem as me by taking off your hose input to the heater, and removing the outer 2 PVC reducer connectors. Then you'll have access and sight to the exchanger input (3" pipe?) and should see what I'm talking about. If the plate moves (or isn't tight) then you most likely have the same issue. [email protected] if you have questions.

Stop using the heater immediately. You are boiling the water inside and this can lead to a dangerous situation if a limit switch fails to act in time.

You will likely find the diverter in the inlet side of the heater is broken. You are looking for a stainless steel plate in the water path. If you can move it by hand, it is broke. It is not replaceable and requires a new heat exchanger assembly to repair it.

Your part number is IDXHXA1101. We sell it as will most pool dealers. If you would like a quote, contact us at www.arrowmotor.net