Technical library / on-site diagnosis

THE FAULT IS NOT ALWAYS WHERE THE SYMPTOM APPEARS.

HIU and CIU symptoms cross electrical, hydraulic and control boundaries. Safe, conclusive diagnosis requires measured conditions and engineering attendance at the property.

Book an engineer visit
ENGINEERING ATTENDANCEMEASURE / VERIFY

Why attendance is required

Remote assumptions lead to unnecessary replacement.

Temperature, pressure, flow, electrical supply and control demand must be observed at the system. Do not remove covers or attempt live electrical or hydraulic work. Request technical support so an engineer can test the complete interface.

Request technical support
TECH / 01

No hot water

Primary temperatures, differential pressure and DHW control response must be measured at the unit.

Book engineering attendance
TECH / 02

No heating

Demand, pump operation and secondary circulation require testing together on site.

Book engineering attendance
TECH / 03

Hot water fluctuating

Dynamic readings under draw-off are needed to separate flow, valve and exchanger faults.

Book engineering attendance
TECH / 04

Pump not working

Electrical command, control mode and hydraulic load require competent verification.

Book engineering attendance
TECH / 05

High return temperature

Return performance must be assessed under load across both sides of the interface.

Book engineering attendance
TECH / 06

Low delta T

Measured flow, temperatures, bypass and valve authority are needed before remediation.

Book engineering attendance
TECH / 07

Apartment cooling

CIU controls, water temperatures and condensation protection require on-site checks.

Book engineering attendance