HVAC

BuildingWrench repair guide

HVAC

Water-Source Heat Pump Not Cooling: Facilities Troubleshooting Checklist

For a water-source heat pump that runs but does not cool, verify thermostat demand, airflow, filter condition, loop-water availability, condensate safeties, and whether neighboring units are affected. Refrigerant and internal electrical diagnosis should be escalated.

Last reviewed 2026-09-12 · General facility-maintenance information, not a substitute for site procedures, manufacturer instructions, codes, or qualified professional judgment.

Diagnose then escalateSkill: Beginner–IntermediateTypical time: 15–30 min
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Safety boundary

Do not bypass safeties, open refrigerant circuits, or perform energized electrical diagnosis unless trained, authorized, and equipped.

Full troubleshooting steps are in Pro

The safety boundary, quick answer and stop-work conditions above stay free. Pro opens the likely causes, symptom table, step-by-step procedure and preventive maintenance for this guide.

Stop and call a licensed professional when

  • Refrigerant diagnosis is required
  • Electrical panel work is required
  • Repeated high/low pressure lockouts
  • Loop water unavailable building-wide
  • Water leak inside cabinet

Mistakes, FAQ, parts and tools

Pro opens the rest of this guide: common mistakes, field FAQ, the parts list, and the tools for the job.

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No Cooling: Full Troubleshooting Guide

Confirm the call for cooling at the thermostat, confirm the unit has power and is not locked out on a safety, then check the two things that cause most no-cooling calls: a loaded filter and a plugged condensate drain with a tripped float switch. Anything involving refrigerant, energized troubleshooting, or gas requires a licensed technician.

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VRF One Zone Not Cooling: How to Narrow Down the Problem

When one VRF indoor unit is warm but the rest of the system is cooling, the failure pattern is the biggest clue. Start with local controls, mode conflicts, airflow, sensors, branch components, and fault codes before assuming a system-wide refrigerant problem.

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Condensate Pump Not Working: Safe Checks Before Replacement

A condensate pump that stops moving water can shut down cooling or overflow. Check safe external power, the reservoir, float movement, and discharge tubing before replacing the pump.

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One Room Is Too Humid: Commercial HVAC Troubleshooting

High humidity in one room can come from excess outdoor air, low cooling runtime, exhaust imbalance, moisture sources, sensor error, or airflow problems. Measure temperature and relative humidity before changing setpoints.