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Emergency HVAC Contractors in Londonderry, NH (2026)

Top 50 of 589 HVAC contractors, in emergency orderUpdated 0 paid placements in this rankingHow we rank

25 of the 50 HVAC contractors on this list post 24/7 hours. 24/7 businesses come first, then same-day, each ranked by CR Score with availability weighted higher.

If you smell gas, leave the building now and call your gas utility or 911 from outside.

The short answer

  1. 1

    #1 for emergency heating and cooling in Londonderry: Heritage Home Service, open 24/7.

Rankings can't be bought. Contractors can't pay to change their rank or score. How we rank

Top emergency HVAC contractors in Londonderry at a glance

Top emergency HVAC contractors in Londonderry at a glance
RankBusinessCR ScoreGoogle ratingBased inHours
1Heritage Home Service944.8★ (7,956)Auburn, 7 mi away24/7
2High Ground Service Pros - Plumbers Electricians & HVAC Technicians924.9★ (2,303)Manchester, 10 mi away24/7
3Southern New Hampshire Plumbing and Heating924.8★ (433)Londonderry24/7
4Walley's Heating & Air914.9★ (793)Nashua, 9 mi away24/7
5A.J. LeBlanc Heating, A/C, Plumbing & Electrical904.8★ (683)Bedford, 9 mi away24/7
6Sanford Temperature Control904.9★ (1,832)Milford, 17 mi away24/7
7LHR Plumbing Heating Cooling and Electric904.9★ (454)Manchester, 9 mi away24/7
8MillTown Plumbing, Heating, Cooling and Electrical904.8★ (2,927)Chelmsford, 17 mi away24/7
9A. Fagundes Plumbing & Heating Inc.904.8★ (1,626)Billerica, 14 mi away24/7
10A. Fagundes Plumbing & Heating Inc.904.9★ (348)Nashua, 9 mi away24/7

Call an emergency HVAC contractor in Londonderry now

24/7 hours mean the business says its phone is answered around the clock. Arrival time depends on where the crew is. Ask for an arrival window when you call.

The 50 emergency HVAC contractors in Londonderry, ranked

24/7 first, then same-day service, then the rest. Each group is in CR Score order on emergency weights. The full ranking of all 589 is on the HVAC contractors page.

Scores below: based on 6 of 8 factors; credentials and recency not yet collected. Hatched segments mark factors we don't have yet.

Top 50 of 589 HVAC contractors by emergency score

#1 to #25 are shown in full above. Here are #26 to #50, in CR Score order; each links to its profile.

HVAC contractors in Londonderry, ranks 26 to 50
RankBusinessCR ScoreGoogle ratingDistance
26Clear All Cooling & Heating875.0★ (54)9 mi
27Ferris Plumbing, Heating & Air874.9★ (77)10 mi
28J. Griffin Heating & Plumbing Inc875.0★ (643)24 mi
29MVP Home Services874.7★ (545)17 mi
30Cool-Rite Mechanical Inc.874.9★ (183)16 mi
31Done right plumbing heating cooling875.0★ (46)9 mi
32Danerik Mechanical, LLC.875.0★ (45)9 mi
33Fuel NRG874.5★ (94)6 mi
34Patriot Heating & Cooling, LLC874.8★ (174)14 mi
35Key Heating & Air Conditioning874.8★ (692)22 mi
36City Fuel864.6★ (101)9 mi
37YurTek - Heating and Cooling865.0★ (86)15 mi
38Druziako HVAC Inc.864.8★ (185)17 mi
39Advanced Quality Air864.8★ (20)5 mi
40Excel Mechanical864.8★ (444)22 mi
41Cal's Air Conditioning & Heating865.0★ (18)6 mi
42Pilot Plumbing, Heating and Cooling | Plumber, Tankless Water Heater Repair & Installation | Heating & AC Repair Sandown, NH865.0★ (51)13 mi
43American Air HVAC864.8★ (223)19 mi
44Georges Heating and Cooling864.3★ (82)6 mi
45Hunter & Sons AC & Cooling864.9★ (94)16 mi
46R.H. Young Cooling and Heating, Inc.864.8★ (265)20 mi
47NextGen Aire854.8★ (271)21 mi
48W L Brady Corporation854.8★ (24)9 mi
49Kingdom Cooling854.5★ (15)5 mi
50Modern Temperature Control854.9★ (96)18 mi

How we ranked emergency HVAC contractors in Londonderry

Emergency lists move 10 points of the CR Score from reputation to availability: 25% and 20%. Availability credits 24/7 hours, same-day service, weekend hours and weekly open hours. 24/7 HVAC contractors are listed first, then same-day, then the rest; ranks follow that order. Paid placement never changes a rank.

Paid placement never changes a rank or score. Featured businesses are paid, labelled, limited to 3 and shown above the ranking, outside it.

Read the full method: formula, sources and exclusions

CR Score factors and weights
FactorWeightComputed from
Reputation25%Bayesian-adjusted Google star rating
Credentials15%Active state license 0.6, bond 0.2, workers’ comp 0.2
Review volume10%log10(reviews + 1) against the list maximum
Recency10%Share of reviews from the last 12 months
Availability20%Weekly open hours, Saturday, Sunday, 24/7 or same-day
Trade focus10%Google main category 1.0, business name 0.7, additional category 0.5
Proximity5%1.0 when based in the city, falling to 0 at the trade’s radius
Completeness5%Website, photos, description, hours, claimed profile (0.2 each)

Emergency HVAC contractors in Londonderry: questions

Which HVAC contractors in Londonderry are open 24/7?

25 on this list post 24/7 hours, including Heritage Home Service, High Ground Service Pros - Plumbers Electricians & HVAC Technicians, Southern New Hampshire Plumbing and Heating, Walley's Heating & Air and A.J. LeBlanc Heating, A/C, Plumbing & Electrical.

Who is ranked #1 for emergency heating and cooling in Londonderry, NH?

Heritage Home Service is #1, with a CR Score of 94 out of 100 on emergency weights.

How are emergency HVAC contractors in Londonderry ranked?

Emergency lists move 10 points of the CR Score from reputation to availability: 25% and 20%. Availability credits 24/7 hours, same-day service, weekend hours and weekly open hours. 24/7 HVAC contractors are listed first, then same-day, then the rest; ranks follow that order. Paid placement never changes a rank.

What should I do before the HVAC contractor arrives?

If you smell gas, leave the building now and call your gas utility or 911 from outside.

How many emergency HVAC contractors here list a phone number?

25 of the 25 businesses ranked in full list a phone number. Tap Call to dial it.

Update log for Londonderry

  1. October 2026: CR Scores recalculated for 589 hvac contractors serving Londonderry.
  2. October 2026: 9 duplicate listings merged.

More emergency and heating and cooling pages