Drain the heating system

What is going on

Draining the TRX150 and its heating circuit is done for service or to protect the system from freezing. Confirm the boiler is isolated and cold before you open any drain, because system water can be hot enough to scald. Keep the water away from the display and control panel.

Likely causes

• Water left in the boiler or low points in a building that will sit cold
• Isolating valves not closed, so the whole system drains
• Air not able to enter, so the lowest points drain slowly

Check in this order

1. Make sure the boiler power and gas are off, and let the water cool.
2. Close the valves of the heating and hot water circuits.
3. Open the system drain valve and collect the water in a container.
4. Drain water from the lowest points of the system.
5. If the boiler is empty on the water side, drain the rest through the lowest points as needed.
6. Check the container for dirt or sludge, which tells you the loop needs cleaning.

More boiler guides

• Access the low voltage wiring connections
• Blocking errors versus lockout errors
• Blower not running
• Blower runs at high speed with burner off
• Boiler bangs or hisses; Lockout 81 delta T
• Burner not running on a call for heat