Choosing a Geothermal Drilling Contractor: Questions to Ask
A good geothermal drilling contractor is licensed for your province, insured, willing to put the loop design, grouting method and pressure testing in writing, and clear about who restores your yard. Ask for those items before you compare anything else.
What should a geothermal drilling contractor be able to show you?
The drilling is the part of a ground-source system you cannot inspect later. Once the boreholes are grouted and covered, the work is buried for decades, so the paperwork matters more than it does for most trades. Start with proof that the crew is allowed to do the job in your province. Drilling and well rules differ across Canada, and some provinces regulate who may drill and how holes must be sealed.
Ask to see the following before you sign anything:
- A current provincial licence or registration for drilling, where one is required.
- Liability insurance and workers’ compensation coverage, with the certificates sent to you directly.
- Training for whoever designs and fuses the loop piping, as many installers use an industry accreditation for ground-loop work.
- Two or three recent jobs on similar ground, with a homeowner you can phone.
Which questions reveal how the loop will be designed?
A contractor who quotes a number of boreholes by rule of thumb is guessing. A proper design starts from a heat-loss calculation for the house and some knowledge of the ground: rock or clay, groundwater, and how well the soil conducts heat. Ask who did the load calculation, what total bore length it produced, and what happens if the first hole shows different geology than expected.
Our guide to geothermal drilling depth and spacing explains why those numbers matter. At Drake Landing, the 144 boreholes were roughly 35 m deep and spaced about 2.25 m apart, a layout chosen for heat storage rather than heat extraction. A home loop works differently, but the principle holds: spacing, depth and ground type were designed together, not guessed.
Also ask whether the plan is a vertical or horizontal loop. The trade-offs are covered in ground loop types, and a contractor should be able to say why one suits your lot.
How do you check grouting and pressure testing?
Grout seals the space around each pipe. It keeps heat moving between pipe and rock, and it stops surface water from running down the hole into an aquifer. Ask what grout is used, how it is mixed, and whether it is pumped from the bottom of the hole upward. Ask for the loop to be pressure tested before and after backfilling, with the readings recorded and handed to you.
Request the driller’s log for each hole. It records depth, the layers encountered, any water found and the grout volume. If a contractor is reluctant to produce a log, treat that as information.
What about site restoration and drilling mess?
Drilling produces a lot of wet cuttings and heavy equipment tracks across the lawn. Agree in writing where the rig will sit, where cuttings will go, who removes them, how trenches to the house will be backfilled and who repairs landscaping. Ask whether utility locates have been booked, since striking a buried line is a common and expensive mistake.
What are the red flags in a quote?
- A price that arrives with no heat-loss calculation behind it.
- No mention of permits, inspections or utility locates.
- Pressure to sign the same day because the rig is nearby.
- A large deposit demanded before any design work.
- Vague warranty wording that does not say who covers the loop, the fusion joints and the indoor unit.
Compare at least three written quotes using the same assumptions, and read what geothermal heat pumps cost for the drivers behind the spread. Prices vary by region and year, so the quotes you collect are the real numbers. For the money side, see geothermal rebates and financing and check current programme terms with your provincial energy ministry or local utility before committing.
Quick answers
Do I need a licensed driller for a geothermal loop?
In many provinces, yes: drilling and well sealing are regulated, and rules vary. Check with your provincial authority and ask the contractor for their registration.
Should I ask for a pressure test report?
Yes. A recorded pressure test on the loop, done before backfill and again after, is a normal expectation and gives you evidence if a leak appears later.
Who is responsible if a borehole is drilled badly?
Responsibility depends on your contract, so get the warranty in writing and confirm who covers the loop, the grout work and the indoor equipment separately.