20 Most Recent Hayward 2001 Series Millivolt Gas Pool Heater 200000 BTU () Questions & Answers

it's possible there is a blockage in one of the lines---those tubes are a very popular place for spiders to build a nest. check especially where you see curves in any of the tubes

Hayward 2001... • Answered on Dec 23, 2018

If the valve "in the heater" you are talking about is the main gas valve, check the regulator, which should be before the main gas valve.

Hayward 2001... • Answered on Dec 03, 2014

There is a pilot light on the millivolt heaters. If you remove the service cover, you should be able to see the pilot. If you are not sure where to look, follow the wire from the ignitor. Where it ends (where the sparker is) is where the pilot flame should be.

Hayward 2001... • Answered on Aug 12, 2014

Hi richardta312,

If you noticed that the temperature has fallen dramatically, it is because there's not enough water is going through the heat exchanger or they are shot or the pressure switch is set for too low a flow. The heater should shut off when the pump turns off or the thermostat has sensed the set temp has been reached. Here are additional steps that you may apply on this issue.

1. Check for water flow problem. Locate the heater and rap the heat exchanger main pipe with the handle end of a screw driver. Check if it will make a popping and rattling noise.

2. Take off the main water connection to the heater and look into the inlet end. Check if the water flow bypass spring had broken off at ends and check if jam downward.

3. The water bypass "spring" looks a lot like a salmon fishing flasher - about 10 inches long, 3inches wide and bent at the ends in opposite directions.Hayward used "epoxy" to attach the both ends to the main copper pipe that makes up the flow-through chamber for the heat exchanger.

4. There is 1/4 inch vertical tube that houses a temperature sensor for the thermostat at the inlet end of the main chamber. Put a pipe clamp on this tube and force the water flow bypass spring up into it's proper position.

Hope it helps.

Thank you for using FixYa.

Hayward 2001... • Answered on Jun 14, 2011

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

First you will need to get a hold of a digital or analog multimeter and set it for the lowest range of Ohms you can. Your safety circuit is a string of several switches all strung together in a row with the gas valve at the end and the beginning of said string. Any one switch being open or a bad connection anywhere in the circuit and the heater will not fire.

You task is to remove one end of the circuit from the valves TH or TT post and put one end of you meter on that wire and the other end on the TH/PP terminal. It will likely read infinite resistance. Leave one meter lead where it is and remove the other. Follow the circuit from the connected lead up to the first switch. Check continuity from the lead left connected to both sides of the switch. If there is continuity to both sides the switch is fine. Keep moving from switch to switch until you find the bad switch or connection. There may be more than one. When the circuit is working properly and there is nothing within the heater to cause it to shut off you should have 5 ohms or less across the entire circuit. Once you get the reading to that level the heater will work as it should

If you are not familiar with the process I described you would be better served hiring a pool technician to perform this repair as you can cause significant damage to the heater if you do not repair it properly.

If this answer does not fix your problem, please comment with additional details prior to rating the answer. Positive feedback is appreciated once your problem is solved!


Hayward 2001... • Answered on Jun 06, 2011

Try bleeding the gas line and clean all the terminals on the wire harness.

Hayward 2001... • Answered on Jun 27, 2010

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

The jet(s) nearest the pilot assembly are clogged. Back them out of the manifold and clean out the spider nest or other debris. That should clear up the problem. And get a new service guy if they didn't take care of this when they were there!

If this answer does not fix your problem, please comment with additional details prior to rating the answer. Positive feedback is appreciated once your problem is solved!


Hayward 2001... • Answered on Jun 01, 2010

This may be caused by condensation (occurring when heating very cold water); a missing or damaged bypass; or excessive water flow through the heater from an oversized pump. Check the heat exchanger for sooting, and make sure the internal bypass is working. Install an external pool heater bypass if necessary.

Hayward 2001... • Answered on May 22, 2010

Before you do anything, check with Hayward as to the minimum flow they require to maintain safe temperatures in the heater. You may have to throttle the heater back. They may have a lower value pressure switch you could use, too.

Hayward 2001... • Answered on May 18, 2010

its trying to start check voltage to fan if ok bad fan motor if no check safety circuit

Hayward Pool &... • Answered on Dec 19, 2020

Could the Error code be HS? That is high temperature limit. Perhaps you' don't have enough flow, allowing the heater to heat the water to a temperature higher, than the thermostat setting. Make sure your bypass valve is closed, allowing full flow through the heater. Check your filter pressure differential , and skimmer baskets.
You didn't give your model number, and there are many models. You can go the Hayward website below and select your exact model number and download the manual. The manual will explain each error code.

Hayward Pool &... • Answered on Jun 07, 2020

Are you sure it has a centrifugal switch? Capacitor start/ capacitor run have been the standard for a good number of years.

Hayward Pool &... • Answered on Oct 26, 2019

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