Question about Hayward H-series Electronic Gas Pool Heater H400
"LO" is simply informing you that the Heater is not sensing proper water flow through it! A Flow Problem.
A special sensor, called a pressure switch is this source. But... That does not mean it is bad - No, it is in most cases just doing its job!
Most common reason - Dirty Filter.
A good cleaning of the cartridges, or maybe a breakdown and recharge of a DE Filter, or a good cleansing backwash of your sand filter, will remedy this situation.
Or... Check for any OTHER reason or situations water flow may be reduced through the heater:
This means "By-Passed Operation"
This mode is for systems with 'Automation' controls. If you don't have an automation system, then your heater has a control dip switch or logic jumper that needs to be undone. But if you have automation, do Nothing, your automated system has control of your heater. Good Luck - hope this helped.
Posted on May 25, 2015
A 6ya expert can help you resolve that issue over the phone in a minute or two.
Best thing about this new service is that you are never placed on hold and get to talk to real repairmen in the US.
The service is completely free and covers almost anything you can think of (from cars to computers, handyman, and even drones).
click here to download the app (for users in the US for now) and get all the help you need.
Posted on Jan 02, 2017
SOURCE: Error code LO
Is the heater installed indoors?? if so you'll need a vent pressure orifice kit.
if not check your water press. (below 18 PSI on filter) Place filter on "recir" if it fires and stays on . it's the pressure.
check to see if all connections a set tight hi-ltd switch wire harness etc.
Posted on Jun 07, 2009
lo usually indicates insufficient water flow and/or pressure switch malfunction.make sure filter is clean and pressure is in normal range
Posted on Jun 21, 2009
BO means that you have bypassed operations. ie automation. if no automation is present then press and hold the Down arrow and Mode button for 3 seconds.
Posted on Aug 23, 2009
One of your limits is not working or not wired up. An easy way to check the limits - Water pressure switch, Hi limits, air pressure switch all of which have 2 wires going to them. Unplug one item and connect the 2 wires together ( paper clip works fine ) Then retest, if problem does not go away remove paper clip and reconnect wires and move to the next limit. The limits are located in the black plastic header. Always make sure water is flowing through the heater at all times while checking the limits.
Posted on Mar 01, 2010
Tips for a great answer:
Mar 07, 2015 | Hayward Pool Products Hayward Universal...
Oct 10, 2012 | Hayward H400FDN Low NOx Natural Gas Pool...
Jun 19, 2011 | Hayward 250kbtu Ng Pool Heater - Inground
Dec 28, 2010 | Hayward 250kbtu Ng Pool Heater - Inground
Apr 08, 2010 | Hayward 350K BTU H SERIES HEATER DRAFT...
Aug 01, 2009 | Hayward H Series Pool & Spa Heater 400k...
Jun 20, 2009 | Hayward H Series Pool & Spa Heater 400k...
153 people viewed this question
Usually answered in minutes!
Step 2: Please assign your manual to a product: