🔥 WHY YOUR POOL HEATER WON’T TURN ON — CHECK YOUR FILTER FIRST

If your pool heater isn’t turning on, don’t panic — and don’t automatically assume the heater is broken. One of the most common and overlooked reasons a pool heater won’t fire up is low water flow caused by a dirty filter.

Pool heaters have built-in safety switches that require proper water flow before they activate. If your filter is clogged with debris, algae, or dirt, the system can’t generate enough pressure to trigger the heater’s flow switch. When that happens, the heater simply won’t turn on.

How to Check If Your Filter Is the Problem

Step 1: Check Your Pressure Gauge

Look at your filter pressure. If it’s 8–10 PSI higher than your normal clean reading, your filter likely needs cleaning.

Step 2: Check Water Flow at the Returns

If the water coming out of the return jets feels weak or reduced, that’s another sign your filter may be restricting circulation.

Step 3: Clean the Filter

Cartridge Filter: Remove and rinse thoroughly. Deep clean if heavily soiled.

DE Filter: Backwash and recharge with fresh DE.

Sand Filter: Backwash until the water runs clear.

After cleaning the filter, restart the system and try turning the heater back on.

Why This Matters

Many heater service calls turn out to be simple flow issues — not mechanical failures. A dirty filter restricts circulation, stresses your pump, and prevents your heater from operating properly.

Keeping your filter clean: ✔ Protects your heater

✔ Improves circulation

✔ Reduces strain on your equipment

✔ Saves you money on unnecessary service calls

If your heater still won’t turn on after cleaning the filter, then it may be time to check sensors, gas supply, or call a professional.

📞 Need Help?

If your heater isn’t firing up or you’re not sure how to properly clean your filter, call Berkys Pool Service at 786-282-486. We’ll inspect your system, restore proper flow, and make sure your heater is operating safely and efficiently before a small issue turns into an expensive repair