Hi. I have a Hayward H350FDN pool heater that is Doing this: • Turn on and Temp at 65 • On for 3 1/2 min then shuts down • Restarts and then on for 5 min, shuts down • Restarts and then on for 2 min, shuts down • Restarts and then on for 8 min, shuts down • Temp 66 • Restarts and then on for 10 min, shuts down • Restarts and then on for 2 1/2 min, shuts down • Restarts and then on for 1 min, shuts down • Restarts and then on for 1 min, shuts down • Restarts and then on for 10 sec, shuts down • Restarts and then on for 40 sec, shuts down • 1F error code I just replaced the heat exchanger prior to this happening. Any ideas????

SOURCE: error code 126

This is a bad thermister or heat sensor. It mounts in your water manifold and if it goes bad no error will show. The bad sensor is telling the heater that the water is to hot and it wont let the heater fire. This is a farley inexpensive part and easy to change out. With a new one it should read the proper temp and call for heat then fire the heater. Good luck.

SOURCE: Hi I hay a Hayward H400 pool heater. It is 2

This is a water flow problem and will be the by-pass assembly in the water manifold. Or their may be an external by-pass wich will be a valve bridging the inlet and outlet pipes for the water. This valve if you have it should be 80-90% closed to force water through heater. Before you do anything be sure to check to be sure the filter and baskets are clean. Often this is the problem.

SOURCE: CE error code on hayward pool heater

CE= Communication Error between Control Module
and Display Interface Assembly
1. Disconnect and then reconnect power to heater.
2. Check for faulty wiring or connection.
Inspect Display Interface Wiring. Ensure Display Interface Plug is securely attached to Control Module. .
3. Control Module and/or Display Interface Assembly
are defective.Replace Control Module and/or Display Interface Assembly.
Here is a linkt oH aywardmanuals:
http://www.haywardnet.com/inground/products/manuals.cfm

SOURCE: Pool heater shuts off after a few second

You didn't indicate your exact model. There are different versions of the H200 series. If it is milivolt then there is no electric, Must have correct milli-volt pilot generator. If it's electronic, check the air flow pressure switch on the combustion air.

SOURCE: hayward pool heater h series

It could be that your gas connection has a blockage that is preventing adequate fuel for from getting to the heater. If that is not the case, try consulting your owners manual for these pool heaters. There is an online copy at the link below.

http://www.backyardcitypools.com/images/Hayward/H100-Manual.pdf