My older hayward h250 is not igniting now
It would appear you have a Hayward H series dual-thermostat pool heater. These systems were designed for use with two temperature thermostats so that the heater could be used as both a spa heater and a pool heater just by switching water valves and switching the selector switch on the heater.
Both thermostats on the heater work exactly the same way, and in fact they are simply duplicate thermostats with a selector switch to choose which temperature setpoint you wish to use. All other elements, functions and features of the control system are the same -- all other control components that are used in the heater are the same components except for these two thermostats. As a result, either thermostat can be used to do the same thing -- set a temperature shutoff limit.
CAUTION: Always turn off the power and gas to the heater and turn off the pool pump when attempting any repair of your H series heater.
CAUTION: The pool heater is essentially a furnace. Only qualified service technicians with proper training and tools should service the heater.
As in your case, if one thermostat does not operate, the other can be used so long as the remainder of the system operates properly. All of the other safety sensors are included in the control system regardless of which thermostat is being used. If one thermostat does not operate the heater but the other does, that malfunctioning thermostat should be replaced. Purchase part number CHXTST1930 and follow the instructions in the package to replace it.
Here's a suggestion: I have found that rotating the thermostats fully counterclockwise during the off-season tends to increase the life of the thermostat.
During the life of your H series heater maintenance needs to be performed due to the dirt and corrosion. The manual recommends cleaning the pilot (or ignitor/flame detector) and the burner tubes once a year, as well as a general cleaning of the various components. Similar to a home furnace, this cleaning helps keep the various systems functioning properly. Occasionally some components will wear out and need to be replace.
Over time the inside of the burner tubes will collect dirt and rust particles. Your manual provides instructions on how to remove the burners for cleaning. This procedure is a bit tricky, so if you're not inclined to repair things (like your furnace) it would be wise to have a professional do this cleaning. In other words, head the cautions listed above. The burner assembly can be disconnected from the heater for cleaning without disconnecting each burner tube. I recommend using a 1.5 inch with 16 inch handle brass tube brush to clean the inside of each burner tube. Material caught in the tube might be difficult to get out -- use a vacuum, then shake with the inlet side down, then vacuum again. You'll know you have removed all the debris when as you shake the assembly it no longer rattles. The exterior can be cleaned with a brass wire or tough nylon bristle brush, then wiped with a soft cloth. Inspect the burner tubes carefully, looking for any cracks or broken welds. If damaged, replace with HAXBRN1930 burner tube. DO NOT USE A DAMAGED TUBE! This can lead to serious problems with your heater and/or danger to those who come in contact with it.
Another source for flame problems is the gas orifices -- especially propane orifices. The gas orifices are located in front of the main burner tubes. Especially in the off season, insects love to wonder in the orifices and build nests, or spiders will build webs. Natural gas orifices are larger and less susceptible, but propane orifices are much smaller and should be checked and cleaned often. A standard household pipe cleaner works well for this job. The orifices point toward the main burners, so it's tight going in this area.
If your heater has a standing pilot (MV series, has a small flame on all the time), it also should be cleaned periodically -- annually is the manual's recommendation. Again, the manual illustrates a procedure to dis-assemble, clean, and re-assemble the standing pilot. The pilot is a little burner, just like the larger burner, so it needs to be clean of dirt and corrosion. It has a manual spark generator. You should be able to hear or see the spark as you press the manual spark generator. If not, the manual spark generator may need a new battery (if so equipped), gap adjustment, or may need to be replaced. The standing pilot has a flame detector. Both the spark tip and the flame detector are constantly in the flame, so they need to be kept clean of corrosion. Use an Emory cloth to gently clean these metal components. If any part of the standing pilot assembly is damaged, replace it with a new part. Consult your manual for standing pilot component parts.
If your heater has an electronic ignitor (ED series) your heater does not have a pilot. Rather, your heater uses a electrically generated spark and a flame detection system to start combustion and monitor the flame's presence. The ignitor has two metal prongs that need to be kept clean and free of corrosion. Your manual illustrates dis-assembly and re-assembly procedures. Use an Emory cloth to gently clean the two metal prongs. The gap between these two prongs is important -- should be 9/64 inch between the closest points. Also, the distance from the ignitor/flame detector to the main burner tube is important. If you see distorted prongs (not straight, different angles, etc.) suspect that the prongs have been damaged. If the ignitor is damaged, replace it with a new ignitor assembly HAXIGN1931.
Now back to operation. I suspect you have an ED series heater (electronic ignition) since you describe a "clicking from the control module". The clicking sound may well be coming from the electronic ignitor (HAXIGN1931). If true, then the system is attempting to initiate combustion. Combustion start steps are: 1. permissives active (yellow LED ON in some models) AND thermostat active (either spa or pool depending on selector), 2. controller starts spark and opens gas valve (green LED ON in some models), 3. controller senses flame detection. 4. If flame is not detected within about 3-5 seconds, controller closes gas valve and stops spark (green LED OFF in some models). 5. If flame continues to be detected, controller turns off spark but leaves open gas valve until either permissives or thermostat goes inactive (OFF). 6. If any permissive goes inactive (OFF), yellow LED goes to OFF (in some models) and combustion is inhibited.
Now to trouble shooting: You describe a "clicking" but the system would not go into combustion. As you can see from the combustion start steps, the likely fault is that the controller cannot detect flame. This typically points to either: 1. No fuel (valve closed, etc.), or 2. flame detector malfunction. First make sure you have fuel, valve open, etc. Next verify that the heater gas valve does actually open. You should hear a metallic "click" as the heater gas valve solenoid operates. (If you do not hear this metallic click, the gas valve or the controller might need to be replaced, or the wiring between them might be broken or disconnected.) In the first few seconds you might not see any flames since the gas needs to travel down the burner tubes to the ignitor. Once combustion initiates near the ignitor, the flame will propagate throughout the burner set rapidly. On this model the flame is difficult to see. I recommend setting a mirror on the heater floor before initiating combustion, then remember to remove once flame is off.
If you've check the fuel and are certain you have fuel to the heater, then the likely fault is in the ignitor/flame detector. The controller provides about 3-4 sparks per second to the ignitor during combustion initiation. You should hear a rapid "clicking" that sounds like the snaps of static sparks. Since you hear a "click", you're probably getting spark but might not be getting flame detection. If the cleaning and adjusting procedure above does not solve the problem, it's likely the assembly needs to be replaced.
As I mentioned above, the gap between the metal prongs on the ignitor assembly is important. Too-wide -- might lead to spark but no flame detection. Even wider -- might lead to no spark at all. Over time the prongs may distort slightly due to combustion temperatures. If left uncleaned or unadjusted, the ignitor will sooner-or-later malfunction. Additionally, corrosion of the metals, both at the spark gap and at the ground base, can lead to higher resistance in the circuit. If the heater is operated outside, corrosion of the metals will be accelerated due to moisture and other contributors from plants and insects.
Oct 11, 2012 |
Hayward Pool Products Hayward H250 250k...