# Make Up Air Unit Toronto | Rooftop Units Toronto Pros

> Make up air unit Toronto: direct + indirect fired MUA repair, replacement and balancing for restaurants and garages. Hood interlocks. 24-hour written quote.

URL: https://rooftopunitstoronto.ca/make-up-air-unit-toronto/

![Direct-fired make-up air unit beside a kitchen exhaust fan on a Toronto restaurant roof](/images/misc/direct-fired-make-up-air-unit-beside-a-kitchen-exh.webp)

Restaurants, Commissaries + Garages

# Make-Up Air Unit Repair, Replacement and Balancing for Toronto Kitchens

Last updated: October 24, 2026

Direct and indirect fired MUA repair, replacement and balancing for restaurants and parking garages.

-   Heavy doors
-   Backdrafting hoods
-   Cold kitchen in winter
-   Dining room odours
-   Burner lockouts
-   Pilot lights blowing out

Book a Site Assessment

[/contact/ →](/contact/)

 

View Pricing

[#pricing →](#pricing)

24-Hour Written Quote

Written per-site quote

-   Parts, labour, crane, permit + HST on one line
-   2-4 hr on-roof emergency response, GTA core
-   Save on Energy rebate filed on qualifying work

Red Seal HVAC-RTSSA G1 + G2ESA + CRE$5M + WSIB

24/7 Dispatch (437) TBD

[tel:+14370000000 →](tel:+14370000000)

-   24-Hour Written Quote (not a sales pitch)
-   24/7 Emergency RTU Dispatch (2-4 hr on-roof GTA core)
-   Red Seal HVAC-R + TSSA + ESA + CRE Chiller
-   $5M Liability + WSIB + COI in 24 Hours
-   Save on Energy Rebate Filed on Your Behalf

1,800+

GTA installs

97%

Uptime

2-4 hr

On-roof, GTA core

48

Sites under contract

Symptoms first

## Is Your Equipment Showing These Signs?

Heavy doors, backdrafting hoods, cold kitchens in January and dining-room odours point to a failed or unbalanced make-up air unit. We repair, replace and balance direct and indirect fired MUAs and verify hood interlocks for restaurants, commissaries and parking garages.

-   Heavy doors
-   Backdrafting hoods
-   Cold kitchen in winter
-   Dining room odours
-   Burner lockouts
-   Pilot lights blowing out

Seeing one of these? 

Book a site assessment

[/contact/ →](/contact/)

 or call dispatch for a 2-4 hour on-roof visit in the GTA core.

## Signs Your Make-Up Air Unit Is Failing

Make-up air unit problems show up in the dining room before anyone looks at the roof. The front door takes two hands to open. Hoods backdraft and smoke rolls into the dining room. The kitchen is freezing in January. Customers smell the fryer at their table. Gas appliance pilots blow out.

All of those point to the same thing: the kitchen exhaust is pulling air out of the building faster than the make-up air unit (MUA) is putting it back. The building runs negative, and every door, flue and crack starts pulling outdoor air in the wrong places.

## Direct vs Indirect Fired MUA

|  | Direct-fired MUA | Indirect-fired MUA |
| --- | --- | --- |
| How it heats | Gas burner in the airstream | Heat exchanger, flue to outdoors |
| Efficiency | Very high | Lower |
| Common uses | Restaurant kitchens, garages, warehouses | Occupancies that need flue-separated heat |
| Typical service | Burner, modulating gas valve, flame safeguard | Heat exchanger, burner, venting |

Our TSSA G1 and G2 techs service both. Brands include **Engineered Air**, **Modine**, **CaptiveAire** and **Greenheck**.

## How We Balance a Kitchen

Balancing is measured, not guessed:

1.  Measure hood exhaust airflow
2.  Measure MUA supply airflow
3.  Check **building pressure** with a **magnehelic gauge**
4.  Adjust MUA fan speed, dampers and controls
5.  Verify the **exhaust hood interlock** so supply runs whenever exhaust runs

The goal is a building that runs neutral or slightly positive. Hood interlocks follow **NFPA 96** practices and the **Ontario Building Code**.

> **The RTU and the MUA are a pair**
> 
> When the MUA is down, the rooftop unit fights hot or cold infiltration and grease coats its coil. That is why we service both on one visit. See 
> 
> 5-ton rooftop units
> 
> [/5-ton-rooftop-unit-toronto/ →](/5-ton-rooftop-unit-toronto/)
> 
>  for restaurant RTU sizing.

## How Much Does MUA Service Cost?

MUA work is quoted per site because burner type, airflow and controls vary widely. Our published data point is a Liberty Village restaurant RTU + MUA repair: **$1,840 on one visit**, tally written before work started. You get a written quote within 24 hours of a site visit. Emergency calls run at standard after-hours rates; see 

emergency rooftop unit repair

[/emergency-rooftop-unit-repair-toronto/ →](/emergency-rooftop-unit-repair-toronto/)

.

## Where We Service Make-Up Air

Restaurants in Liberty Village, King West and The Queensway, commissaries in the 

Etobicoke

[/service-areas/etobicoke/ →](/service-areas/etobicoke/)

 industrial area and Rexdale, light manufacturing in Concord and 

Vaughan

[/service-areas/vaughan/ →](/service-areas/vaughan/)

, and parking garages in condo podiums across the GTA, usually on the same roofs as the 

commercial rooftop units

[/ →](/)

 we service. For ventilation that needs dehumidification and energy recovery rather than kitchen replacement air, see 

DOAS systems

[/doas-system-toronto/ →](/doas-system-toronto/)

.

Published pricing

## How Much Does Make-Up Air (MUA) Cost in Toronto?

MUA work is quoted per site because burner type, CFM and controls vary widely. Our published data point: Liberty Village restaurant RTU + MUA repair, $1,840 on one visit. Written quote within 24 hours.

25/50/25 payment on installs: 25% at order, 50% on install day, 25% on commissioning sign-off. Net-30 for commercial and PM accounts. 

See all pricing

[/pricing/ →](/pricing/)

.

### Make-Up Air (MUA) pricing

CAD + HST

| Service | Price | Timeline |
| --- | --- | --- |
| Restaurant RTU + MUA repair (Liberty Village) | $1,840 | One visit |
| RTU after-hours / weekend call | $425-$650 | 2-4 hr |
| MUA repair, replacement or balancing | Per-site quote | 24-hr written quote |

Case study | Liberty Village, Toronto | Liberty Village restaurant strip

## Liberty Village restaurant RTU + MUA repair

A Liberty Village restaurant had backdrafting hoods and a dead RTU in July. The MUA had a burner and airflow fault leaving the kitchen negative, and the RTU had a failed fan motor and grease-coated coil. Both units were repaired and the airflow rebalanced on one visit, with the tally written before work started.

Equipment

Restaurant RTU + make-up air unit

Size

One restaurant

Turnaround

One visit

Price

$1,840

Why property teams pick us

## Why Choose Rooftop Units Toronto Pros for Make-Up Air (MUA)?

### RTU + MUA together

We service the rooftop unit and make-up air unit on one visit, because they work as a pair.

### TSSA gas techs

Direct and indirect fired burners serviced by TSSA G1 and G2 licensed technicians.

### Measured balancing

Airflow and building pressure measured, not guessed, with a magnehelic gauge.

### Hood interlocks verified

Exhaust and make-up air interlocked so the kitchen cannot run negative.

### Restaurant priority

Restaurants go to the front of the 24/7 emergency queue.

### Scheduled around service

Non-emergency work between services or after close.

What to expect

## How Does Our Make-Up Air (MUA) Work?

1.  01
    
    ### Pressure + airflow test
    
    Exhaust and supply airflow measured, building pressure checked with a magnehelic gauge.
    
2.  02
    
    ### Burner + controls check
    
    Burner, modulating gas valve, flame safeguard, filters and controls tested by TSSA techs.
    
3.  03
    
    ### Written quote
    
    Repair, replacement or rebalancing priced in writing within 24 hours.
    
4.  04
    
    ### Fix + balance
    
    Repairs made, airflow rebalanced and hood interlock verified so exhaust and supply run together.
    

Field photos

## Our Make-Up Air (MUA) Work

Recent GTA rooftops and mechanical rooms. Click any photo to enlarge.

### Before + After

![Failed MUA with burner lockout and clogged filters](/images/cards/failed-make-up-air-unit-with-burner-lockout-light-.webp)

Before

![MUA running after repair with balanced airflow](/images/cards/same-make-up-air-unit-running-with-new-filters-cle.webp)

After

Liberty Village restaurant RTU + MUA repair, $1,840, one visit.

Client Records

## What Clients Say About Our Make-Up Air (MUA)

> "Our Liberty Village kitchen had backdrafting hoods and a dead RTU in July. They fixed the MUA and the rooftop unit in one visit for $1,840, with the tally written before they started."

DRDaniel R.Restaurant owner, Liberty Village

> "The front door used to need two hands to open. Once they rebalanced the make-up air, it closes normally and the dining room stopped smelling like the fryer."

MGMaria G.Restaurant manager, The Queensway

> "Our indirect fired MUA locked out every cold morning. A failed flame rod and a dirty burner, fixed before the morning shift."

TSTony S.Commissary operator, Etobicoke

> "They serviced the garage make-up air in our podium and documented everything for the board."

HKHelen K.Board president, Liberty Village

> "Our King West retail plaza had three RTUs down over a long weekend. First unit cooling by Saturday noon, all three up before Monday open. Written diagnostic same day."

PSPriya S.PM, King West retail

## RTU offline or chiller alarm?

Red Seal tech on the roof in 2-4 hrs across the GTA core. Call (437) TBD.

(437) TBD

[tel:+14370000000 →](tel:+14370000000)

 

Emergency Service

[/emergency-rooftop-unit-repair-toronto/ →](/emergency-rooftop-unit-repair-toronto/)

Buyer questions

## Make-Up Air (MUA) FAQs

Still have a question?

A Red Seal lead answers, not a call centre. Written quote within 24 hours.

Book a Site Assessment

[/contact/ →](/contact/)

(437) TBD

[tel:+14370000000 →](tel:+14370000000)

### How much does make-up air unit repair cost in Toronto?

MUA work is quoted per site because burner type, airflow and controls vary widely. Our published data point is a Liberty Village restaurant RTU + MUA repair at $1,840 on one visit. You get a written quote within 24 hours of the site visit.

### What is the difference between direct and indirect fired make-up air?

A direct-fired MUA burns gas directly in the airstream, which is very efficient and common in kitchens and garages. An indirect-fired MUA heats air through a heat exchanger, so combustion products never enter the airstream, which some occupancies require.

### Why are my restaurant doors hard to open?

The building is running negative: the hood is exhausting more air than the MUA is supplying. That usually means the MUA is off, locked out, undersized or out of balance.

### Why do my hoods backdraft or smoke spill into the dining room?

Without enough make-up air, the hood cannot pull properly. Smoke and odours spill out. Balancing supply to exhaust and verifying the hood interlock fixes it.

### Why is my kitchen cold in January?

If the MUA burner is not firing or the modulating gas valve is stuck low, the unit pushes outdoor air in without heating it. Burner, flame sensor and gas valve checks find the cause.

### What is a hood interlock?

An interlock ties the exhaust hood and MUA together so supply air runs whenever exhaust runs. It prevents the building from going negative and is part of safe kitchen ventilation under NFPA 96 practices and the Ontario Building Code.

### How do you balance a make-up air system?

We measure exhaust and supply airflow, check building pressure with a magnehelic gauge, then adjust fan speed, dampers and controls until the building runs neutral or slightly positive.

### Do you service parking garage make-up air units?

Yes. Garage MUAs in condo podiums and office buildings are serviced and documented for boards and property managers.

### Which MUA brands do you service?

Engineered Air, Modine, CaptiveAire, Greenheck and other common commercial make-up air brands.

### Can you service the RTU and MUA on the same visit?

Yes, and on restaurant roofs we usually do, because the two units affect each other.

Keep the whole roof covered

## Related Services

![Dedicated outdoor air system unit with energy recovery on a Toronto office roof](/images/misc/dedicated-outdoor-air-system-unit-with-energy-reco.webp)

[/doas-system-toronto/ →](/doas-system-toronto/)

### 

DOAS Systems

[/doas-system-toronto/ →](/doas-system-toronto/)

DOAS install and service with energy recovery for ventilation and IAQ upgrades.

Details + pricing

[/doas-system-toronto/ →](/doas-system-toronto/)

 

![5-ton RTU beside a kitchen exhaust fan and make-up air unit on a restaurant roof](/images/misc/5-ton-packaged-rooftop-unit-next-to-a-kitchen-exha.webp) From $9,500

[/5-ton-rooftop-unit-toronto/ →](/5-ton-rooftop-unit-toronto/)

### 

5-Ton Rooftop Units

[/5-ton-rooftop-unit-toronto/ →](/5-ton-rooftop-unit-toronto/)

5-ton RTUs for restaurants and small offices, sized for kitchen and occupancy loads.

Details + pricing

[/5-ton-rooftop-unit-toronto/ →](/5-ton-rooftop-unit-toronto/)

 

![Commercial rooftop unit with an open panel under work lights at dusk in Toronto](/images/misc/service-van-headlights-and-a-commercial-rooftop-un.webp) From $425

[/emergency-rooftop-unit-repair-toronto/ →](/emergency-rooftop-unit-repair-toronto/)

### 

Emergency Rooftop Unit Repair

[/emergency-rooftop-unit-repair-toronto/ →](/emergency-rooftop-unit-repair-toronto/)

No-cool, no-heat and tripped-breaker calls answered by a Red Seal tech, not a call-centre ticket.

Details + pricing

[/emergency-rooftop-unit-repair-toronto/ →](/emergency-rooftop-unit-repair-toronto/)

## Don't See Your GTA City?

Coverage from Toronto to Pearson, Mississauga to Markham. Call 

(437) TBD

[tel:+14370000000 →](tel:+14370000000)

 for a 24-hour written quote.

All Service Areas

[/service-areas/ →](/service-areas/)

 

Get a Written Quote

[/contact/ →](/contact/)

![Packaged rooftop units on a Toronto commercial roof at dusk](/images/misc/toronto-commercial-rooftop-at-dusk-with-a-row-of-p.webp)

24/7 dispatch | 2-4 hr on-roof GTA core

## Ready to Book Make-Up Air (MUA)?

Site assessment, then a written quote within 24 hours. Parts, labour, crane, permit and HST on one line.

Book a Site Assessment

[/contact/ →](/contact/)

 

Call (437) TBD

[tel:+14370000000 →](tel:+14370000000)

-   24-hour written quote
-   Save on Energy filed for you
-   Red Seal + TSSA + ESA + CRE
-   $5M liability + WSIB