Markool Heating Cooling PlumbingHVAC contractor in Frederick, MD
Markool Heating Cooling Plumbing is an HVAC contractor at 5304C Kings Ct, Frederick, MD 21703, ranked #3 of 272 HVAC contractors in Frederick and rated 4.9 from 547 Google reviews. Open 24 hours a day, 7 days a week.
Frederick, MDUpdated 0 paid placements in any rankingHow we rank
Key facts
| Address | 5304C Kings Ct, Frederick, MD 21703Get directions |
|---|---|
| Phone | (301) 732-4244 |
| Website | markoolhvac.com |
| Hours | Open 24 hours, 7 days a week |
| Google rating | 4.9 from 547 Google reviews |
Service area
Serves Frederick and 11 towns within 25 miles: Ballenger Creek, Spring Ridge, Urbana, Brunswick, Walkersville, Green Valley, Clarksburg, Linganore, Damascus, Poolesville and Thurmont.
Based in Frederick, MDView on map
Opening hours
| Day | Hours |
|---|---|
| Monday | Open 24 hours |
| Tuesday | Open 24 hours |
| Wednesday | Open 24 hours |
| Thursday | Open 24 hours |
| Friday | Open 24 hours |
| Saturday | Open 24 hours |
| Sunday | Open 24 hours |
- Open 24/7
- Open evenings — no
- Open Saturdays
- Open Sundays
- Emergency service
Typical heating and cooling prices
| Job | Low | Typical | High |
|---|---|---|---|
| AC replacementPer system, installed (unit plus labor); typical range of customer-reported jobs. US national range | $3,887 | $5,978 | $8,073 |
| Furnace replacementPer system, installed; typical range of customer-reported jobs. US national range | $2,823 | $4,814 | $6,896 |
Market ranges for the trade, checked October 2026, not a quote from this business. Ask for a written estimate.
Compare nearby HVAC contractors
| Business | Rank | CR Score | Google rating | License verified | Saturday | Sunday | Distance away |
|---|---|---|---|---|---|---|---|
| Markool Heating Cooling Plumbing (this business) | — | 93 | 4.9 (547) | — | Yes | Yes | |
| Wenbrooke Services - Electrical, Plumbing, Heating and Air | #1 | 93 | 4.8 (1,208) | — | Yes | Yes | 3.1 mi |
| Larry & Sons Plumbing, Heating, Cooling, Drain & Electrical | #2 | 93 | 4.8 (932) | — | Yes | Yes | 3.5 mi |
| Smock Heating & Air | #4 | 92 | 5.0 (1,623) | — | Yes | Yes | 5.4 mi |
Questions about Markool Heating Cooling Plumbing
How is Markool Heating Cooling Plumbing ranked in Frederick?
Markool Heating Cooling Plumbing is ranked #3 of 272 HVAC contractors in Frederick by CR Score, with 93 out of 100 as of October 2026. The score weighs reputation, credentials, review volume, recency, availability, trade focus, proximity and profile completeness. No business can pay to change its rank.
What are Markool Heating Cooling Plumbing’s hours?
Markool Heating Cooling Plumbing is open 24 hours a day, 7 days a week. Its listed hours are Open 24 hours, 7 days a week. On Saturdays it is open Open 24 hours, and on Sundays Open 24 hours. Hours come from the business listing; holiday hours may differ.
What areas does Markool Heating Cooling Plumbing serve?
Serves Frederick and 11 towns within 25 miles: Ballenger Creek, Spring Ridge, Urbana, Brunswick, Walkersville, Green Valley, Clarksburg, Linganore, Damascus, Poolesville and Thurmont. The list is based on the business's location and the usual service radius for heating and cooling. Confirm your address is covered when you call.
What do Google reviews say about Markool Heating Cooling Plumbing?
Markool Heating Cooling Plumbing has a rating of 4.9 from 547 Google reviews. The CR Score adjusts the star rating for review count, so a high rating from a few reviews counts for less than the same rating from many.
How do I contact Markool Heating Cooling Plumbing?
Call Markool Heating Cooling Plumbing on (301) 732-4244. The business is at 5304C Kings Ct, Frederick, MD 21703. Its website is linked in the key facts on this page. Ask for a written estimate before any work starts.
Own Markool Heating Cooling Plumbing? Claim this profile.
Claiming is free. Correct your hours, trades and service area. The CR Score is recalculated from corrected data; payment never changes it.