Canada-wide gas boiler information · On-site service in Greater Vancouver, BC
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Comparison
Verdict in brief
De Dietrich MCA Pro 45 and De Dietrich MCA Pro 65 are two condensing boilers from the De Dietrich MCA Pro Series line. Published ratings: De Dietrich MCA Pro 45 at 34–156 MBH input, 146 MBH output and 94% efficiency; De Dietrich MCA Pro 65 at 34–235 MBH input, 222 MBH output and 94% efficiency. De Dietrich MCA Pro 65 lists 79 MBH more input than De Dietrich MCA Pro 45 (235 MBH against 156 MBH). Both list the same published efficiency of 94%. The published shipping weight differs: De Dietrich MCA Pro 45 lists 117 lb dry / 130 lb wetted, while De Dietrich MCA Pro 65 lists 133 lb dry / 147 lb wetted.
Published manufacturer figures. Input and output are kept separate; blanks mean the manufacturer did not publish that value.
| Specification | De Dietrich MCA Pro 45 | De Dietrich MCA Pro 65 |
|---|---|---|
| Minimum input (as printed) | 34 MBH | 34 MBH |
| Maximum input (as printed) | 156 MBH | 235 MBH |
| Minimum heat output | 33 MBH | 45 MBH |
| Maximum heat output | 146 MBH | 222 MBH |
| Firing | Modulating, on/off, remote 0–10 V | Modulating, on/off, remote 0–10 V |
| Weight (dry / wetted) | 117 lb dry / 130 lb wetted | 133 lb dry / 147 lb wetted |
| Heating supply / return | 1-1/4" male NPT | 1-1/4" male NPT |
| Gas connection | 3/4" male NPT | 3/4" male NPT |
| Fuel | Natural gas or propane (LPG) | Natural gas or propane (LPG) |
| Thermal efficiency (CSA certified) | 94 % | 94 % |
| Vent / combustion air | 3" single pipe / 80–125 mm concentric | 4" single pipe / 100–150 mm concentric |
| Operating water temperature range | 68–190 °F (CPVC / PP / SS) | 68–190 °F (CPVC / PP / SS) |
| CSA certified installation altitude | Max 4,500 ft / 1,370 m (Canada) | Max 4,500 ft / 1,370 m (Canada) |
Published ratings: the De Dietrich MCA Pro 45 is rated 34–156 MBH input, 146 MBH output and 94% efficiency; the De Dietrich MCA Pro 65 is rated 34–235 MBH input, 222 MBH output and 94% efficiency. De Dietrich MCA Pro 65 lists 79 MBH more input than De Dietrich MCA Pro 45 (235 MBH against 156 MBH). Both list the same published efficiency of 94%.
The vent / combustion air differs: the De Dietrich MCA Pro 45 lists 3" single pipe / 80–125 mm concentric, while the De Dietrich MCA Pro 65 lists 4" single pipe / 100–150 mm concentric.
Both records print the same input (34 MBH), turndown (Modulating, on/off, remote 0–10 V), water connections (1-1/4" male NPT) and gas connection (3/4" male NPT), per the cited sources.
De Dietrich
The De Dietrich MCA Pro 45 is a condensing wall-hung boiler rated 34–156 MBH input and 33–146 MBH output at 94.0% CSA thermal efficiency, with 1-1/4" heating connections and a 117 lb dry weight.
De Dietrich
The De Dietrich MCA Pro 65 is a condensing wall-hung boiler rated 34–235 MBH input and 45–222 MBH output at 94.0% CSA thermal efficiency, with 1-1/4" heating connections and a 133 lb dry weight.
The De Dietrich MCA Pro 65 lists 235 MBH, against 156 MBH on the De Dietrich MCA Pro 45, per the cited documentation.
Both list the same efficiency of 94%.
A consultation includes a heat-loss review so the size is right the first time.
On-site service in Greater Vancouver, BC. ROMA lists “Open 7 days” on its site; call to confirm same-day availability.
Sources and verification
Facts checked September 9, 2026. Last updated September 9, 2026. Technical reviewer: not yet assigned.