T M Johnson Bros, Inc

Category

HVAC

Address

Cambridge, MN

Data checked

November 6, 2026 (OpenStreetMap)

Before You Hire

Facilities usually schedule HVAC contractors at least twice a year, before cooling and heating seasons. Ask:

• Do you take commercial work, and do you service buildings like ours?
• Can you send a certificate of insurance naming us as additional insured?
• Are your technicians EPA Section 608 certified to handle refrigerant?
• Do you service our equipment type and brand (rooftop units, chillers, boilers)?
• What does a service agreement include, visit by visit?

All 8 questions to ask →

Hiring Tips

• Change filters on a schedule set by your dust load, often every 1–3 months.
• Keep a list of every unit with its model, serial number and age.
• Compare repair quotes against the unit's age before replacing it.

Getting several quotes? Line them up in the quote comparison tool and check the contract checklist before you sign.