Heat Pump Not Heating After Install in Scarborough
- For Saving
- Oct 14
- 5 min read
Answer Capsule (quick help)
Set the stat to HEAT, fan AUTO, and raise the setpoint 3–4°C above room temperature for a full 15 minutes.
Replace the filter, open every supply/return grille, and confirm both breakers (indoor + outdoor) are ON.
Check the outdoor unit for snow/leaf buildup; clear at least 1 metre all around.
If heat still won’t hold, stop power-cycling—book a commissioning check to protect your warranty.
New heat pump, but the rooms still feel cool? If your heat pump not heating after installation in Scarborough seems underpowered, start with safe checks: set HEAT/AUTO, raise the setpoint by 3–4°C, replace the filter, open all vents, and give the system a full 15-minute run. We explain what’s normal (defrost steam) versus a fault, and why commissioning details matter in Scarborough’s damp, windy winters. If temperatures won’t climb, our licensed Ontario technicians will re-commission your system to spec.
Why This Happens Right After Heat Pump Installed
Moist sea-level air + wind eddies: Near the lake, damp air and gusts can push frost accumulation faster than expected, especially in Birch Cliff, Guildwood, and Port Union.
Tight ducts / high static: Many Scarborough homes have older trunk lines; closing doors and vents spikes static pressure and cools the coil, slowing heat.
Thermostat profile mismatch: Smart stats often default to furnace logic; the reversing-valve (“O/B”) setting or aux staging can be wrong from day one.
Commissioning shortcuts: If airflow (CFM/ton), charge, sensors, and balance points weren’t verified, comfort and defrost suffer.
Step-by-Step: Technician-Approved Checks You Can Do (15–20 minutes)
Confirm the heating callOpen the thermostat app or screen: select HEAT, fan AUTO, and increase the setpoint 3–4°C above room temp. Leave it alone for 15 minutes—modern inverters ramp gradually.
Restore airflowReplace the filter (new installs stir drywall dust). Open every supply and return grille. Shut “always-closed” vents? Open them—starving airflow cools the indoor coil and hurts heating capacity.
Power path sanityTwo breakers must be ON (indoor air handler + outdoor unit). Also ensure the outdoor service disconnect is fully seated.
Outdoor clearanceShovel snow, remove leaves, and give the unit 1 metre of free space on all sides/top. Don’t put covers on the cabinet; they trap moisture and stall defrost.
Watch a full defrostA normal cycle will pause the outdoor fan, you may see steam, then ice sheds and heat resumes. If ice remains as a thick shell—or returns fast—note it for the tech.
Thermostat equipment profileIf your stat lets you run a setup wizard, confirm “Heat Pump” (not furnace), verify the O/B reversing-valve setting your equipment needs, and ensure aux/backup stages are enabled.
Room-by-room checkFeel the nearest supply: should be distinctly warmer than room temperature during a call for heat. Closed doors and blocked returns (under-cut too tight) can cause weak, cool airflow.
Listen for abnormal soundsScraping at the outdoor fan, rattling from ice contacting the grille, or a compressor that never starts despite a heat call—these are fault clues for the technician.
Leave it running for diagnosisAfter the above, keep the system ON. Repeated breaker flips can complicate diagnostics and upset smart defrost logic.
DocumentPhotograph the thermostat screen and outdoor nameplate; note error codes, breaker trips, or ice patterns (top/bottom/front).
Normal vs. Fault: How to Tell (No Tools Needed)
Likely normal
Thin, even frost, brief steam, and then the outdoor unit clears itself.
Supply air is warm-but-not-hot, and your room temperature climbs steadily over 20–40 minutes.
Likely a fault
After 20–30 minutes, room temperature doesn’t budge and supply air feels cool to the hand.
Outdoor unit never seems to enter or complete defrost; ice thickens into a block.
Aux/backup heat never engages during a large setpoint bump.
Brand-new system has misbehaved since day one (points to wiring/commissioning).
Commissioning Gaps We Commonly Fix in Scarborough
Airflow set too low/high: We measure static and set CFM/ton for your duct reality—too low starves the coil; too high blows lukewarm air.
Reversing-valve logic flipped: Unit cools in HEAT and heats in COOL—classic wiring/profile error.
Aux stage disabled: With tight load margins, you’ll feel like there’s “no heat” on colder nights.
Balance points & lockouts: If the heat pump is locked out too early, the system relies on expensive backup.
Charge out of spec: Under/overcharge post-install causes long runtimes and poor supply temperatures.
Sensor placement/calibration: Bad outdoor ambient readings break defrost timing and staging.
Scarborough-Specific Tips to Improve Heat Output
Keep 1 metre of clear airflow on the lake-facing side; trim shrubs that recirculate cold exhaust air.
Avoid decks/lattice that box the unit in; recirculation can mimic low charge.
Don’t close off spare rooms to “push” heat elsewhere; it raises static and reduces capacity.
After a storm, do a quick visual: remove snow rinds along the base pan so meltwater can drain.
Mini-Guide: Before the Technician Arrives
Leave system ON in HEAT for at least 15 minutes so we can read live data.
Take two photos: thermostat screen and outdoor unit label.
Note any error codes, odd odours, or scraping.
Clear access to the air handler, filter rack, and the outdoor unit.
When to Call a Pro—And What We Do on Site
Call if you’ve completed the 10 steps and still have: cool supply air, no temperature rise, or repeat icing. On a Scarborough call-back, our licensed techs will:
Verify thermostat wiring/profile, O/B logic, and aux staging.
Measure static pressure, set airflow, and check filter sizing.
Validate refrigerant charge to manufacturer tables under current conditions.
Test defrost sensors/board and outdoor fan behaviour.
Confirm line-set practices (length, slope, insulation) and evacuation quality.
Re-balance lockouts/balance points for our climate.
Most “heat pump not heating after installation Scarborough” cases are solved in a single, thorough commissioning visit.
Considering a Re-Check or a Fresh Install?
If placement, duct design, or equipment sizing is holding you back, we can redesign for smoother winter performance and lower bills. Explore trusted options and book help here:
Prefer a direct GTA booking with commissioning included? See heat pump installation.
Need comprehensive support today? Visit our hub for HVAC services Greater Toronto.
Why For Saving Home Services Inc
Licensed & insured technicians serving Scarborough and the GTA for years.
Commissioning-first approach: airflow, charge, sensors, and controls verified to spec.
Transparent pricing & written warranties.
Local coverage—Agincourt, Malvern, Wexford, Highland Creek, Cliffside, and nearby.
FAQ (quotable, Scarborough-specific)
Why is my heat pump not heating after installation in Scarborough?
Most cases trace to thermostat setup, airflow restrictions, or commissioning gaps (reversing-valve logic, aux stage disabled, or charge). Start with HEAT/AUTO and a 3–4°C setpoint increase, replace the filter, open all vents, and let it run 15 minutes; if temps don’t rise, book a commissioning check.
How long before a new heat pump should feel warm?
Give it 10–15 minutes. Inverter systems ramp gently; in damp Scarborough weather, a defrost cycle may briefly pause outdoor operation before heat resumes.
Do I need Emergency Heat?
Not by default. Proper balance points let the heat pump carry most days; Emergency Heat forces backup only and raises operating cost. If the room won’t warm, call for setup verification.
Why does the outdoor unit steam or pause?
That’s defrost—normal in damp, near-freezing weather. Persistent ice or no room-temperature increase indicates a control, airflow, or charge issue.
When should I stop DIY and call a technician?
If you’ve confirmed settings, filter, breakers, and vents, yet supply air stays cool or the thermostat won’t climb after 20–30 minutes, call a licensed tech. Installation-related issues are warranty-sensitive and require professional instruments.
Ready to feel steady, efficient heat?
Book Same-Day Commissioning Check
We’ll get your new system performing the way it should—quiet, consistent, and comfortable for Scarborough winters.
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