
HVAC
"Absolutely fantastic experience with George. I got home from a work trip at 5:00pm to discover my furnace s blower fan had burnt out. George came that evening and stayed until 9:30 to fix it, at a price that was more reasonable than those quoted by others. He was a true professional and I would recommend him to anyone."
Jake B. in December 2019

Rtu package units, Furnaces, Heat pumps , and 2 more
"They did an excellent job - responsive and very fast."
Victor K. in February 2023

Sewer & Water Line Replacement - We Can Repair or Replace a Water or Sewer Line Without Destroying Your Front Lawn - Call for a Free Water or Sewer Line Inspection, Plumbing - Water Heaters, Leaky Faucets, Running Toilets, Sump Pump Repair & Installation & Much More, Heating - We Service All Makes & Models, 2 Year Warranty on Repairs, Annual Service Plans for Cleaning & Maintaining Equipment , and 2 more
"After signing up with Servicepro, I was on the phone with Horizon within 10 minutes. This was about 9:30 PM. They offered to come and fix the problem he next morning (day before Thanksgiving) but I declined because I was going away. Anyway I scheduled a 10 am appointment for Friday November 28, 2008 and they were very prompt. The techinitian expalined the issue and my heat was up and running within the hour. Very impressed with their service and professionalism. I am now signed up for annual check up for my HVAC system and would not hesitate to recommend them to others."
kirk A. in December 2008
HVAC
"Sergii was able to fit us in his schedule in the midst of a severe heat wave. He and his team worked expeditiously and were able at install a new air conditioning system as well as align the existing furnace with the new system the same day. The air conditioning system is working fabulously well and I have no complaints. Will definitely recommend him for the services he provides in the HVAC world."
Betty H. in July 2024

Geothermal Heating and Cooloing, HVAC
"Great company. I had my AC fixed. Their staff, from April who handles admin, to Wayne who diagnosed our machine and found the leak for the cost of the initial visit whereas other companies wanting to charge us a $1000 to do that. To Thomas, who did a professional job, making sure I was informed of the process, answering any questions I had, and taking care of any concerns. He was professional and very personable. I can't say how much they cost compared to other contractors but right off the bat they saved me $1000 which puts them far ahead of the crowd in my book. Even if it was a bit of a premium, its a premium I am happy to pay for good craftsmanship and piece of mind."
6D1D356AE65C9B05447D86BA307AE43BDC1BD4E5807F79D2A35FFF57D63B30CC D. in May 2026
In business since 1980
About us: "In 1972, Donnelly’s Cooling, Heating & Plumbing began serving Pennsylvania residents with premier plumbing services and later expanded to add their superior HVAC services. As the area’s top choice for plumbing, heating, and cooling service, we’re proud to offer unmatched professionalism and quality results. With same-day and emergency services, our team is always available for your home service needs. Plus, with service for all brands and free estimates, you can trust you’re in excellent hands with our team."

Plumbing, Electric Installations, HVAC Installations , and 2 more
"I should have written this review a year ago when the work was done. I needed a new heater. A neighbor recommended Marshall Services. I have found them to be a knowledgeable, family-owned team that truly stands out. They’re remarkably adaptable to change—adjusting plans smoothly when new needs arise—and their communication is excellent: clear, proactive, and easy to understand. From the first conversation, their honesty and transparency inspired my confidence, and every interaction since then reinforced that trust. Most importantly, you can count on them. They follow through on commitments, keep you updated without asking, and deliver quality work with genuine care. The combination of expertise, reliable service, and that family-owned touch made the entire experience seamless and stress-free. Marshall Services is my go-to HVAC company and has my highest recommendation."
3E501AEB98CC34BC356F259DE7649D52FDFEF0D5D357D4626A81A19BC3D89858 E. in May 2026
Gwynedd Valley Heating & Furnace Contractors are rated 4.5 out of 5 based on 1606 reviews of 1606 pros.
The HomeAdvisor Community Rating is an overall rating based on verified reviews and feedback from our community of homeowners that have been connected with service professionals. See individual business pages for full, detailed reviews.
If you're looking for Heating & Furnace Systems Contractors that serve a different city in Pennsylvania, here are some popular suggestions:
Find additional Pennsylvania Heating & Furnace Systems Contractors
Find out how HomeAdvisor can help your business