Archived SolarAttic Troubleshooting Hub
PCS1 • PCS2 • PCS3 — Diagnosis, Fixes, Manuals & PDFs
Own an older SolarAttic system? This page is a centralized troubleshooting and documentation hub for archived PCS1, PCS2, and PCS3 solar attic pool heater models. Use it to diagnose common issues, confirm correct operation, and access manuals, wiring guides, plumbing diagrams, and troubleshooting PDFs.
Looking for best performance today? Our current PCS4 systems extend your pool season while helping cool your attic.
Quick Start: Identify Your Model
Choose your system below to jump to the correct troubleshooting section:
Before You Troubleshoot: Safety + Do/Don’t Checklist
Many “no heat” calls are caused by simple setup issues (timers, valves, low flow, clogged filter, incorrect bypass settings).
Start here:
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Confirm the pool pump runs during peak sun hours (commonly late morning through late afternoon).
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Ensure filter is clean and water flow is strong.
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Verify bypass/flow valve positions are correct.
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Confirm attic is hot (these systems rely on solar-heated attic air).
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Check for obvious leaks, loose ducting, or crushed flex/pipe.
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Link: PCS Do's and Don'ts
Fast Diagnostic: What Symptom Matches Your Issue?
Use this to route the customer to the right fix.
Symptom A: “Pool isn’t heating”
Most common causes:
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Pump not running during sun
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Low attic temperature
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Low water flow
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Valve/bypass set incorrectly
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Heat exchanger flow restriction
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Sensor/controller not calling for heat (PCS2/PCS3 setups)
Symptom B: “Fan not running / unit appears dead”
Most common causes:
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No power / breaker
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Timer mis-set
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Wiring/relay issue
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Controller not calling (PCS2/PCS3)
Symptom C: “Low water flow / high pressure / bubbles”
Most common causes:
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Dirty filter
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Air in plumbing
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Restriction in heat exchanger
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Improper bypass/valve setup
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Plumbing layout issues
Symptom D: “Water leak”
Most common causes:
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Union/connection leak
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PVC/flex PVC issue
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Heat exchanger fittings
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Freeze damage / cracks (seasonal)
Symptom E: “Noisy vibration / rattling”
Most common causes:
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Loose mounting
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Duct resonance
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Fan imbalance
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Hardware loosened over time
Common Fixes (Applies to PCS1 / PCS2 / PCS3)
1) Confirm Correct Pump Runtime
These systems work best when your pump runs during strong sun.
Fix: Set timer so your pump is ON during midday/afternoon sun.
2) Restore Proper Flow
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Backwash/clean filter
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Ensure skimmer basket/pump basket is clear
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Confirm valves are fully open where required
Fix: Re-test flow after cleaning.
3) Verify Bypass/Flow Valve Setup
Many installs use a bypass to keep proper flow through the exchanger.
Fix: Set bypass/flow valve per the manual and re-check water temp rise.
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Diagram For Using A Proportioner T-Valve To Control Flow Rate
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PCS2 Plumbing
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SolarAttic Solar Pool Heater Auto System Package PCS2
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PCS1 Plumbing
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PCS1 Flowreversal
4) Electrical / Wiring Basics
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Confirm breaker is ON
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Confirm timer outputs power
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Confirm connections are tight and dry
Actual Electrical Wiring Must Comply With National, State & Local Codes where applicable!
PCS1 Troubleshooting (Archived)
Best For: Legacy PCS1 owners needing manuals, wiring, plumbing, troubleshooting steps, or system package info.
PCS1: “Pool Not Heating”
Checklist
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Pump timer ON during sun
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Filter clean / strong flow
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Bypass valve set correctly
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No air trapped in lines
Fix path
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Clean filter and baskets
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Confirm pump runtime during peak sun
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Verify bypass/flow valve
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Inspect exchanger connections for restriction/leaks
PCS1: “Fan Not Running”
Checklist
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Power present
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Timer functioning
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Wiring connections tight
Fix path
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Confirm breaker and timer
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Inspect wiring per PCS1 manual
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If still dead, document symptoms for tech support
PCS1: “Low Flow / Air in Lines”
Fix path
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Clean filter
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Bleed air (if applicable)
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Check plumbing layout and union seals
PCS1 Document Library (Buttons)
PCS2 Troubleshooting (Archived)
Best For: PCS2 owners using valve + controller/sensors configurations.
PCS2: “No Heat / Low Heat Output”
Most common causes
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Pump not running during sun
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Valve not switching correctly
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Sensor placement or wiring issue
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Controller settings not calling for heat
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Low flow
Fix path
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Confirm pump runtime during sun
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Verify valve position changes when heating is needed
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Check sensors and controller wiring
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Confirm plumbing is per PCS2 install guide
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Verify flow through exchanger is not restricted
PCS2: “Valve Not Operating”
Fix path
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Check actuator wiring and controller output
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Confirm actuator orientation and stops
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Confirm controller is powered and reading sensors
PCS2: “Controller / Sensor Fault”
Fix path
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Verify sensor placement (correct locations)
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Check sensor wiring continuity
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Confirm controller supply voltage
PCS2 Document Library (Buttons)
PCS3 Troubleshooting (Archived)
Best For: PCS2 owners using valve + controller/sensors configurations.
PCS3: “System Running But Not Heating”
Most common causes
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Pump runtime not aligned with sun
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Low flow through exchanger
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Controller not switching (auto systems)
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Attic airflow restriction
Fix path
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Confirm pump schedule (midday sun)
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Verify strong flow and clean filter
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Confirm bypass/valve configuration
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Check controller/sensor readings (if equipped)
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Inspect ducting for obstructions/loose connections
PCS3: “Controller Not Activating Heat”
Fix path
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Confirm sensor placement and wiring
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Verify controller setpoints
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Confirm controller has power and outputs to relay/valve
PCS3: “Wiring / Relay Issues”
Fix path
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Confirm relay wiring per PCS3 guides
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Verify voltage at timer/controller output
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Inspect for corrosion/loose terminals
PCS3 Document Library (Buttons)
Archived Models: When It’s Time to Upgrade
If your PCS1/PCS2/PCS3 system needs major repair, upgrading can restore performance and simplify control.
PCS4 advantages:
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Newer airflow + heat transfer improvements
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Manual, Automatic, and “No Controls” automation-ready options
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Better compatibility with modern pool equipment
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Continues SolarAttic’s “cool attic while heating pool” benefit
Need Help From SolarAttic?
Still stuck? Contact us with a few quick details and we’ll help you get back to swimming fast.
When contacting support, include:
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Model (PCS1/PCS2/PCS3)
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Photos of plumbing pad + attic unit + controller (if applicable)
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Pump schedule
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Filter condition
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Symptom and when it started
Archived SolarAttic Pool Heaters Troubleshooting Articles
SolarAttic Pool Heater Not Heating? Here’s What to Check First If your SolarAttic pool heater isn’t heating, the good news is most issues are simple flow, valve, or control settings—not a failed heat exchanger. SolarAttic systems depend on proper water flow through the solar loop, correct valve position, and (for automatic systems) correct controller + sensor operation. Start by confirming your pump is running during the warmest part of the day and the system is actually sending water through the attic loop. Most common reasons a SolarAttic pool heater won’t heat: The system is bypassing the attic loop (valve set wrong or actuator not moving). Low flow prevents heat transfer through the exchanger. Controller is not calling for heat (sensor placement, wiring, settings). Run time is outside the best solar window (midday is best). Quick Checklist (5 minutes) ☐ Pump is running long enough during peak sun hours (typically midday) ☐ Valve is set to send water through the SolarAttic loop (not bypass) ☐ Water returning to pool feels similar to normal flow (not restricted) ☐ No visible leaks at equipment pad or attic line entry/exit ☐ Filter is clean and pump basket is clear ☐ If automatic: controller display is on and sensors are connected ☐ If automatic: actuator moves when heat is called for ☐ Solar loop pipes feel warmer during operation (when safe to touch) When to call for help: If flow is normal, valve is switching, and you still see no temperature rise on sunny days, your configuration may need a sensor/valve calibration or a flow balance adjustment.
Low Flow Through the Heat Exchanger (Causes + Fixes) Low flow is one of the biggest reasons a SolarAttic system underperforms. The heat exchanger needs steady circulation to pick up and transfer heat. When flow drops, you may notice weak returns, air bubbles, no heating, or a controller that cycles unexpectedly. Common Causes Dirty or undersized filter / clogged pump basket Closed or partially closed valves on the solar loop Bypass valve set incorrectly Debris or restriction in piping (especially after service or winterizing) Air trapped in the system (after draining/refill) Flex PVC kinked or piping route causing restriction Actuator stuck mid-position (partially open/closed) Fixes (in order) Clean filter and pump basket (fastest win). Confirm all valves are fully open where they should be (especially solar loop). Verify bypass orientation: confirm water is being directed through the attic loop. Bleed air: run pump, check for air at returns; purge if your setup allows. Inspect piping route: look for kinks, crushed flex PVC, tight bends, or collapsed sections. Check valve actuator position (PCS2/PCS3): ensure full travel to “solar on.” Recheck after changes: observe return strength and heating performance on a sunny cycle. Pro tip: If heating improves when you manually force the valve to “solar on,” the issue is often actuator/controller, not plumbing.
Valve Actuator Not Switching (PCS2/PCS3): What It Means + What to Do On PCS2 and PCS3 systems, a valve actuator is commonly used to automatically direct water through the SolarAttic loop when heat is available. If your actuator won’t switch, the system may stay in bypass—meaning little to no heating. Symptoms Pool isn’t heating even on sunny days Actuator never moves (or only hums/clicks) Valve appears stuck in one direction Controller shows “heat” but water isn’t routed to solar Common Causes No power to actuator (breaker, timer, wiring issue) Controller not calling for heat (sensor reading / wiring / settings) Actuator gears stripped or stuck Valve body seized from debris or age Actuator installed misaligned with valve shaft Quick Fix Checklist ☐ Confirm controller display is powered and active (if automatic system) ☐ Confirm pump is running during expected solar heating period ☐ Check actuator wiring connections (loose terminals are common) ☐ Try a manual override (if your actuator has a toggle/lever) ☐ Verify valve can rotate freely (actuator removed, if safe) ☐ Confirm actuator is mounted correctly and not binding If the valve turns manually but actuator won’t: the actuator is likely the problem. If the valve won’t turn manually: the valve body may be seized/restricted.
Controller GL235 Basics (PCS2/PCS3): How It Works The GL235 controller helps PCS2/PCS3 systems heat efficiently by comparing temperature readings and switching the system into “solar heat” mode only when it can actually add heat. Think of it as the system’s brain: it decides when to move water through the solar loop and when to bypass. What the GL235 Typically Controls Valve actuator (routes water to solar loop) Sensors (temperature inputs used to determine when to heat) On/Off logic (prevents heating when solar conditions aren’t favorable) Common GL235 Questions “Controller has power but doesn’t heat.” Most often: sensor issue, wiring issue, or the controller isn’t seeing a temperature advantage. “Controller heats at the wrong times.” Timer/run schedule or sensor placement may be causing incorrect calls. “Controller calls for heat but valve doesn’t move.” Actuator power/wiring or a stuck valve. GL235 Quick Checklist ☐ Display is on / controller is powered ☐ Sensors are firmly connected and not damaged ☐ Pump timer schedule overlaps the best solar window ☐ Actuator wiring is secure and matched to correct terminals ☐ When heat is called, actuator completes full travel to “solar on” Best practice: Run the pump during the strongest solar window (typically midday) so the controller has the best chance to add heat efficiently.
Winterizing & Freeze Prevention (Leak Prevention) Freezing conditions can crack fittings, split pipes, and create spring leaks—especially in attic-routed systems. Proper winterizing protects the solar loop, the equipment pad plumbing, and the attic piping path. Why winterizing matters When water freezes, it expands. That expansion can damage: Piping and fittings Valves and unions Heat exchanger components Sensor wells and related hardware Winterizing Checklist (Leak-Prevention Focus) ☐ Shut down heating mode and place valve in a safe bypass position ☐ Drain the solar loop completely (attic route + pad plumbing) ☐ Open/loosen unions where applicable to prevent trapped water pockets ☐ Remove or protect sensors if your setup requires it ☐ Confirm no low spots hold water (common cause of freeze cracks) ☐ In spring, pressure-check or visually inspect before full operation ☐ Re-tighten unions, check seals/gaskets, and run a short test cycle first Signs you may have freeze damage (spring startup) Drips at unions or fittings when pump starts Air entering system (bubbles at returns) Sudden loss of flow through solar loop Actuator/valve behaving differently than last season Tip: Most “mystery leaks” after winter are from trapped water in a low spot or valve body—focus winterizing on draining completely and eliminating trapped pockets.
Archived SolarAttic Pool Heaters Troubleshooting FAQ
Solar Attic Pool Heater Not Heating – FAQs
Why is my solar attic pool heater not heating the pool? The most common reason a solar attic pool heater is not heating is that water is not being directed through the attic loop. This is usually caused by a valve set to bypass, a valve actuator not switching, low flow through the system, or a controller not calling for heat. Start by verifying pump runtime during peak sun hours and confirm the valve is sending water through the solar loop.
How do I know if water is flowing through my SolarAttic system? You can check flow by confirming the valve position and feeling for strong return flow at the pool. During sunny operation, attic loop pipes may feel warmer (when safe to touch). If the system is bypassing, the attic piping will remain cooler and you may see no temperature rise.
Should my SolarAttic heater run all day? Not necessarily. For best results, run the pump during peak solar hours (typically late morning to mid-afternoon). Running outside strong solar windows may circulate water without gaining heat.
Valve Actuator Not Switching (PCS2/PCS3) – FAQs
Why is my solar pool heater valve actuator not switching? If your valve actuator is not switching, it may not be receiving power, the controller may not be calling for heat, wiring could be loose, or the valve body may be stuck. First confirm the controller is powered and calling for heat during sunny conditions.
How do I manually test my SolarAttic valve actuator? Many actuators include a manual override switch or lever. If manually switching the actuator moves the valve and heating improves, the issue may be electrical or controller-related. If the valve won’t move even manually, the valve body may be seized.
Can I replace just the actuator on my PCS2 or PCS3 system? In most cases, yes. If the valve body rotates freely and plumbing is intact, replacing only the actuator is often sufficient. Always confirm compatibility with your controller and voltage configuration before replacement.
Low Flow Through Heat Exchanger – FAQs
What causes low flow in a SolarAttic heat exchanger? Low flow is commonly caused by a dirty pool filter, clogged pump basket, partially closed valves, air trapped in the system, kinked flex PVC, or a stuck valve actuator. Even small restrictions can significantly reduce heating performance.
How do I increase flow through my solar pool heating system? Start by cleaning the filter and pump basket. Then confirm all valves are fully open and properly positioned for solar heating. Check for air in the system and inspect piping for kinks or tight bends. Proper flow is essential for efficient heat transfer.
Can low flow damage my SolarAttic system? While low flow usually just reduces heating efficiency, severe restriction can increase pressure and stress fittings or valves. Correcting flow issues quickly prevents long-term wear and improves performance.
Controller GL235 Basics (PCS2/PCS3) – FAQs
What does the GL235 solar controller do? The GL235 controller monitors temperature conditions and automatically directs water through the solar loop when heating is possible. It controls the valve actuator and ensures the system only heats when solar energy can increase pool temperature efficiently.
Why is my GL235 controller on but not heating? If the GL235 is powered but not heating, it may not be detecting a temperature advantage, sensors could be miswired or damaged, or the pump schedule may not align with peak solar hours. Check sensor connections and confirm proper runtime scheduling.
How do I reset my GL235 solar controller? Most GL235 controllers reset by cycling power off and back on. If problems persist after reset, inspect wiring, verify sensor placement, and confirm actuator operation.
Winterizing / Freeze Prevention – FAQs
How do I winterize my solar attic pool heater? Winterizing involves draining all water from the attic loop and equipment pad plumbing, opening unions to prevent trapped water, and placing the valve in a safe bypass position. Complete drainage prevents freeze expansion damage.
What happens if my SolarAttic system freezes? If water freezes inside the system, it can crack pipes, fittings, valves, or heat exchanger components. Spring startup may reveal leaks, reduced flow, or air entering the system. Proper winter drainage prevents these issues.
How do I know if I have freeze damage? Signs of freeze damage include leaks at unions or fittings when the pump starts, weak flow, unexpected air bubbles, or valve irregularities. Inspect attic piping and pad connections carefully before full seasonal startup.