Gas heaters and heat pumps diagnosed before anything is quoted — including the flow faults that look like heater faults. $150 service call across Twinsburg, Solon, Hudson and the Route 91 corridor.
Gas heaters and heat pumps across Pentair's range, including the MasterTemp, UltraTemp and ETi families, plus older Pentair units still in service on plenty of pools around here.
A $150 service call covers up to the first hour of diagnosis or repair.
Before anything else, because it accounts for a large share of Pentair heater calls and it is the least expensive possible outcome — often no part at all.
Rising filter pressure restricts flow. Check the pressure against your clean baseline first — see pool filter repair.
The commonest cause on any pool where a variable speed pump was fitted and not properly commissioned. The pump is fine, the heater is fine, and the speed assigned to the heating cycle is too low. The fix is a setting. See variable speed pool pumps.
Which does happen and is a genuine heater-side repair.
A heater that will not fire on a schedule but fires when you run it manually is a flow problem, not a heater problem.
Every heater has a minimum water flow it will accept, monitored by a flow-switch. Below that flow the switch refuses and the heater will not light — exactly as designed, because firing a burner without adequate flow damages the exchanger.
What causes it:
A pump losing prime, or a suction-side restriction.
Why it matters commercially: replacing a heater in this situation solves nothing and costs a great deal. It is the single most expensive misdiagnosis in pool service, and it is avoidable with a pressure reading and a flow check.
A pool heater flow switch
Pentair heaters display fault codes, and yours is telling you something specific.
We are not going to list and decode them on this page, and the reason is worth stating: we do not publish a manufacturer's fault codes unless we are working from that manufacturer's own documentation. Getting one wrong would send someone to the wrong component with the power on.
What to do instead: the code definitions for your specific unit are in the Pentair documentation for that model — the manual, or Pentair's own support material. And when you call us, read us the code. It genuinely shortens the visit, because it tells us which system to arrive prepared for.
The distinction matters because the two types fail differently and suit different seasons.
Gas heaters burn natural gas or propane and heat the water directly. Fast, and unaffected by air temperature. Faults cluster around gas supply and the ability to ignite cleanly, venting, the heat exchanger, and scale — a gas heater that has quietly lost output with nothing else changed usually needs a de-lime rather than a part. A gas unit run at too low a return temperature will also condense flue gas inside the cabinet and corrode from the inside, which shows as rust streaking below the burner tray.
Heat pumps move heat out of the outside air rather than making it. Efficient in warm weather, and their output falls as the air cools. Faults cluster around the compressor, the reversing valve, refrigerant charge, fan motors and defrost behaviour.
A pool heater control panel showing a fault
If you are not sure: a gas heater has a gas line and a flue. A heat pump looks like an air-conditioning unit with a large fan on top and no gas connection.
The one piece of advice most heater pages have no reason to give.
A heat pump has an ambient floor. Because it draws heat from the air, its output falls with air temperature and effectively floors out in cold weather — which here means April and October, the exact months most people bought a heater to use. A Pentair heat pump is a sound choice for holding temperature through June to August at low running cost. For genuinely extending the season, gas does something a heat pump physically cannot.
Sizing decides whether it ever satisfies. A heater is BTU-rated for a volume of water and a temperature rise. We size against your actual pool — surface area, wind exposure and whether it is covered all change the answer, and an undersized unit runs continuously and never reaches setpoint. See pool heaters.
Winterizing decides whether it survives. A heater with water left in the exchanger over a Northeast Ohio winter splits it, and a split exchanger is a replacement rather than a repair — and not a warranty matter, because it follows from how the pool was closed. A proper close purges the heater rather than assuming it self-drains.
“M&G has serviced our in ground pool for the past 10+ years. Seasonal opening & closing, replacing heaters, pumps and a number of aggravating repairs that Matt & his crew have handled correctly at a fair price. Recommend highly.”
Read us the code when you call — it usually narrows the job before we arrive.
Pentair heaters are frequently paired with Pentair automation, and when a heater misbehaves on a schedule the controller is worth checking as carefully as the heater.
Common patterns: a heating cycle assigned a pump speed too low for the flow-switch; a temperature sensor reading a location rather than the water; a schedule conflict between heating and filtration. All three look like heater faults from the house. See pool automation.
The inside of a pool automation panel
We do not use an age rule. Depending on its age and condition a heater may be worth repairing or may need replacing, and a diagnostic settles it.
The deciding factor is usually the heat exchanger, whose condition is set by water chemistry rather than years. Scale and corrosion are what finish exchangers, and both come from chemistry — so a Pentair heater that spent its life on well-balanced water can be sound at ten years while one that ran at low pH can be done at five.
Where a repair will hold, we repair. Where the exchanger is gone, we say so rather than sell the same repair twice. See pool heater replacement.
A heat exchanger tube bundle furred with calcium scale
We service Pentair across the equipment pad — see Pentair pool pump repair.
We also work on Hayward, Raypak, Jandy, Sta-Rite, Fluidra and Zodiac: Hayward pool heater repair, Raypak pool heater repair, and the full list on brands we service.
Products we install carry the full manufacturer's warranty, which varies by manufacturer and generally runs between one and three years. We do not offer a separate workmanship guarantee, and nothing on this page should be read as one.
A pool equipment pad with pump, filter and heater
M & G Pools services in-ground pools exclusively. We do not service, repair or supply equipment for above-ground pools, and we do not service hot tubs or spas.
That is nearly always flow rather than the heater. Every heater has a minimum flow its flow switch will accept, and below it the heater refuses to light — by design, because firing without adequate flow damages the exchanger. The usual causes are a filter that needs cleaning or a variable speed pump running too slowly for the heating cycle. Both are settings or maintenance, not a heater replacement.
The definitions for your specific unit are in Pentair's documentation for that model. We deliberately do not publish decoded manufacturer codes unless we are working from that manufacturer's own documentation, because a wrong code sends someone to the wrong component with the power on. Read us the code when you call — it tells us what to arrive prepared for.
It comes down to the heat exchanger, and its condition is set by water chemistry rather than age. Scale and corrosion finish exchangers, and both come from chemistry — so a heater on well-balanced water can be sound at ten years while one that ran at low pH can be done at five. A $150 service call covers up to the first hour of diagnosis.
For holding temperature through June to August at low running cost, yes. For extending the season, less so — a heat pump draws heat from the outside air, so its output falls as the air cools and effectively floors out in April and October, which are the months most people want a heater for. Gas does something a heat pump physically cannot in cold weather.
Yes. Pentair heaters are often paired with Pentair automation, and when a heater misbehaves on a schedule the controller is worth checking as carefully as the heater — a heating cycle assigned too low a pump speed, a sensor reading its location rather than the water, or a schedule conflict all present as heater faults from the house.
