Combustion Blowers for Gas Boilers, Water Heaters and Premix Burners

Appliances this family is built for

• Condensing boilers — premix blower feeding a venturi, high pressure through a tight heat exchanger.
• Wall-hung boilers — the 118 and 130 mm EC sizes: to 129 m³/h, to 3,800 Pa.
• Gas water heaters, power-vent models included.
• Premix burners — LWGE118S-05, LWGE130S-01, LWGE148S-05/06, LWGD108M-01.
• Pellet, biomass and charcoal burners, ovens — AC LWGA11S to LWGA70S.
• Flue extraction — LWGE150S-01, LWGD150L-01/150M-02: to 165 m³/h, to 556 Pa.

The EC series is catalogued for appliances of roughly 6 kW to 200 kW. Above about 260 m³/h a housed scroll blower is the better answer, the flue-extraction sizes being the exception: see the centrifugal blower hub, forward-curved, single inlet and wheels and impellers.

How we supply combustion blowers

One line, because it changes how you audit us: combustion blowers are engineered and specified by LONGWELL, built to LONGWELL drawings, inspected to LONGWELL standards — full statement on our China centrifugal blower manufacturer and OEM blower factory page. Our own Yuyao lines are cross-flow fans and motor winding (factory), not these.

EC and DC combustion blowers — LWGE and LWGD

The modulating parts: brushless motor, control board inside the blower, speed set by your controller.

• Die-cast aluminium housing, specified to hold a 4,000 Pa leak test.
• Anti-static plastic impeller; LWGE148S-05 uses a spark-proof impeller in an aluminium frame.
• PWM input 1–6 kHz, FG tachometer output, locked-rotor and current-limit protection; LWGE148S-05 is specified for 72 h locked rotor.
• IP20 and class F insulation (class B on the 115 V 60 Hz 097 series) are catalogue design ratings, not third-party certifications; the approved datasheet binds.
• LWGE148S-05: −10 to +70 °C, 10–90 % humidity, 30 cm drop test, 184.2 × 190.7 × 149.2 mm outline.
• Model code: LW + G + A/D/E + blade diameter + voltage letter + serial. Here U 115 V, S 230 V, L 12 V DC, M 24 V DC; full decode on the hub.

Catalogue figures. Maximum airflow and maximum static pressure are separate points on one curve, never simultaneous, so do not multiply them. For LWGE148S-05 the specification sheet and the catalogue differ slightly (about 200 m³/h and 3,300 Pa against 196 and 3,090); the quotation states which applies. Selection is confirmed against the duty point — airflow, static pressure, voltage, control mode — and validated on your burner head.

AC combustion blowers — LWGA

LWGA splits in two. The 085 to 180 sizes: 220–240 V 50 Hz, 30–75 W, 1,300–2,500 rpm, 82–172 m³/h, 185–597 Pa. The LWGA11S to LWGA70S sizes are single-phase two-pole shaded-pole motors, class F or H, catalogued by outlet velocity, not flow.

Catalogue data, single-phase 220–240 V 50 Hz. Every figure on this series is re-confirmed against the released specification sheet before quotation.

Flue gas and ambient temperature limits

Two limits matter, and they differ. Gas path: the DC flue-extraction versions are aluminized steel, catalogued for continuous flue gas to 180 °C, excursions to 240 °C. Ambient: LWGE148S-05 is rated −10 to +70 °C at the motor and electronics. In a sealed cabinet ambient usually binds first, so send the cabinet temperature you measure.

Speed control and air/gas ratio control

The EC and DC interface is PWM in at 1–6 kHz with FG tachometer output back: the controller sets a duty cycle, FG closes the loop, and it reads real speed, not commanded speed. That is what holds a burner's turndown.

Ratio control comes two ways and the blower has to suit yours. Pneumatic: the venturi's negative pressure signal drives the gas valve, so the pressure characteristic is part of the calibration and the curve cannot be swapped casually. Electronic: speed and valve position come from a stored map, trimmed by ionisation or O₂ feedback, so speed repeatability matters more; say which you use. On a burner running most of its hours below full fire an EC or DC blower pays back its price difference; at one fixed fire rate it usually does not.

Certification status — read this before you specify

This family holds no CE, ETL or UL certification in LONGWELL's name, whatever approval marks an older gas data sheet may show. What exists:

• ISO 9001, 14001 and 45001 systems covering how this family is specified, inspected and released.
• CE certificates covering the AC forward-curved LWFA108–450 range only — not combustion blowers.
• An ETL Recognized Component file covering part of the EC and DC forward-curved range, inside a defined model rule. Combustion blowers sit outside it.
• Air performance tested to the AMCA 210 method; sound measured in a semi-anechoic room (calibration report SSD202500326) — a method and a calibration, not an approval.

The appliance carries the gas approval under the standard for your market and the blower is assessed inside that file; we supply drawings, materials list, motor data and samples for your notified body. Numbers and dates: quality and certifications.

Samples, tooling, MOQ and lead time

Samples of catalogue models ship in 1–3 days, production runs in 15–30 days, warranty is 12 months; we export to 30+ countries. Outlet angle and spigot, inlet diameter, lead length and connector, PWM range, label and packaging are routine changes. A new housing or impeller diameter needs tooling, quoted with its amortisation split, which then sets the MOQ — see the OEM process.

Questions from boiler and heater OEMs

Do your combustion blowers carry CE?

No, and we will not apply a CE mark to this family for you. Our CE certificates cover the AC forward-curved LWFA108–450 range. The gas approval sits with the finished appliance, and we support that file with drawings, declarations and samples.

Can you build to our drawing?

Yes, the normal case. LONGWELL owns the drawing set here, so a customer-specific housing, impeller, outlet angle or harness is a drawing change on our side and a tooling quote on yours.

PWM or 0–10 V?

PWM at 1–6 kHz with FG feedback is the catalogue interface here. If your controller only has 0–10 V, say so early: that is standard on our EC centrifugal blowers and DC brushless blowers.

Which model fits a 24 kW condensing boiler?

Not from kW alone — the same output needs very different pressure depending on heat exchanger and flue. Send airflow and static pressure at maximum and minimum fire, supply voltage and the ratio-control scheme. Wall-hung premix duties usually land on LWGE118S-05 or LWGE130S-01, condensing duties on the 148 sizes.

Where do I find curves and CAD?

Curves and CAD for the housed ranges are on select.longwellfans.com; gas listings sit on longwellfans.com. Outline drawings and P-Q data come with the quote.

Send the duty point and we will quote. Upload burner data or a drawing on the request a quote page — airflow and static pressure at maximum and minimum fire, supply voltage, control mode, cabinet temperature. Back come a model, a sample lead time and any tooling cost, usually by the next working day.