The Elterm Battalion (AsBIII) is a commercial electric central-heating boiler built for continuous industrial duty, available in four factory outputs — 30kW, 36kW, 42kW and 48kW — all running on a 400V three-phase supply. It uses industrial-grade solid-state relay switching and three-stage PID power modulation to bring a building up to temperature smoothly rather than in full-power bursts, and it's PV-ready, so it can throttle its own draw to cooperate with an on-site solar installation. A volt-free switching contact for a second heat source makes it equally suited as the primary boiler for a commercial building or as a backup/peak source alongside a heat pump or gas boiler. Units can be cascaded in parallel for outputs up to 1.5MW, and each boiler is configured to order with a typical lead time of 5–7 working days.
~99.5%
Electric-to-heat efficiency
400V 3-Phase
Power supply
95°C
Max C.H. flow temperature
5–7 Days
Typical lead time
Qualified Installation Required
Electrical connection, commissioning and any work carried out with the casing removed must be done by a qualified electrician in accordance with UK wiring regulations (BS 7671) and Part P. Adequate overcurrent and residual current (RCD) protection is mandatory, and the installation must include a means of disconnection at all poles with a contact gap of at least 3mm.
No Expansion Vessel Supplied — Model & Naming Notes
The Battalion (AsBIII) range is supplied without an expansion vessel, safety valve or safety group. On a sealed/closed heating system these must be sized for the installation and fitted by the installer before commissioning.
Built to Order — Customisation & Lead Time
This range is configured to order: choose your 30/36/42/48kW output, add the optional D.H.W. priority pack, or cascade multiple units for outputs above 48kW. Typical lead time is 5–7 working days. Contact us for a tailored quote on cascade or multi-unit schemes.
PV-Ready & Heat Pump Cooperation
A built-in energy counter and adjustable maximum-power lock let the boiler limit its own draw so it preferentially uses available solar generation before pulling from the grid. A volt-free switching contact can also hand control to a second heat source — useful where this boiler backs up a heat pump or bridges a gap before a gas connection is available.
Industrial SSR Switching
Solid-state relays replace mechanical contactors, so the frequent on/off cycling of continuous commercial duty doesn't wear down physical contacts — a key reason this range is rated for industrial and continuous operation rather than domestic-only use.
Three-Stage PID Modulation
Each output splits its heater bank into three roughly equal stages (for example 16-16-16kW on the 48kW unit) and uses PID logic to bring the system to temperature progressively, cutting short-cycling and reducing the size of the electrical demand spike at start-up.
Equal Phase Loading
Heater banks are wired so each of the three supply phases carries a matching share of the load, keeping the incoming three-phase supply balanced rather than skewed onto a single leg — important for larger commercial connections where phase imbalance can trip protection or draw penalties.
Bivalent Heat-Source Switching
A volt-free contact disconnects a second heat source (such as a gas boiler) the moment the electric boiler switches on, and reconnects it when the electric boiler switches off — the mechanism behind its role as a heat pump or gas boiler backup.
Cascade-Ready Design
Multiple Battalion units can be linked and sequenced together, which is how Elterm rates this range for combined outputs of up to 1.5MW — useful once a single building's demand outgrows the 48kW ceiling of one unit.
Watch Dog & Anti-Stop Protection
A processor monitoring routine, quadruple overheat cut-out and a periodic anti-seize pump run protect the unit through long, unattended commercial operating cycles rather than relying on manual checks.
Model comparison — all variants 400V 3-phase, 50Hz
| Model |
Elterm Code |
Rated Output |
Heater Configuration |
Modulation Stages |
Fuse Protection |
Supply Cable |
| Battalion 30kW |
116030 |
30kW |
6 × 3kW + 6 × 2kW |
10-10-10kW |
3 × 50A |
5 × 16mm² |
| Battalion 36kW |
116036 |
36kW |
12 × 3kW |
12-12-12kW |
3 × 63A |
5 × 16mm² |
| Battalion 42kW |
116042 |
42kW |
6 × 4kW + 6 × 3kW |
14-14-14kW |
3 × 80A |
5 × 25mm² |
| Battalion 48kW |
116048 |
48kW |
12 × 4kW |
16-16-16kW |
3 × 80A |
5 × 25mm² |
General specification — common across all outputs
| Specification |
Details |
| Boiler type |
Commercial electric central-heating boiler (space heating only) |
| Control |
Industrial Basic LED automation, PID regulator, 3-stage output modulation (33/66/100%) |
| Electric-to-heat efficiency |
Approx. 99.5% |
| Max C.H. flow temperature |
Up to 95°C (industrial series) |
| Temperature setting range |
5–95°C |
| Energy efficiency class |
D (ErP space-heater scale, spectrum A+++ to D) |
| Cabinet dimensions (W × H) |
410mm × 680mm |
| Pipework connections |
2 × 1" BSP external thread (flow & return) |
| Cable entry |
Ø29.8mm, from the top or rear of the casing |
| Circulating pump |
Factory-fitted electronic pump |
| Expansion vessel / safety group |
Not supplied — must be provided by the installer on closed systems |
| Optional D.H.W. pack |
3-way D.H.W. priority valve + cylinder sensor + activation code (code 100003); requires a separate cylinder with coil, min. 12kW |
| Cascade capacity |
Multiple units may be cascaded for a combined output of up to 1.5MW |
| Compliance |
Ecodesign 2009/125/EU, RoHS 2011/65/EU, EMC 2014/30/EU, Low Voltage 2014/35/EU |
| Warranty |
3 years (36 months) when registered at eltermlondon.co.uk within 30 days of installation |
| Lead time |
5–7 working days (configured to order) |
Sizing guide by building floor area (manufacturer reference — outputs above 48kW require cascaded units)
| Insulation standard |
250m² |
300m² |
400m² |
500m² |
600m² |
700m² |
800m² |
1000m² |
| Energy-efficient (20–25cm insulation, A+/A) |
12kW |
15kW |
18kW |
24kW |
24kW |
30kW |
36kW |
42kW |
| Standard (10–15cm insulation, B/C) |
18kW |
24kW |
30kW |
36kW |
42kW |
54kW |
60kW |
72kW |
| Energy-intensive (0–5cm insulation, D/E) |
30kW |
36kW |
48kW |
60kW |
72kW |
84kW |
96kW |
126kW |
Does the Battalion 30–48kW boiler come with an expansion vessel or safety valve?
No. Per Elterm's installation manual, the Battalion (AsBIII) range is supplied without an expansion vessel, safety valve or safety group. On a sealed/closed heating system these must be sized for your installation and fitted by your installer before commissioning.
Can this boiler be customised or scaled up for larger buildings?
Yes. Choose from four factory outputs (30/36/42/48kW), add the optional D.H.W. priority pack, or cascade multiple units in parallel — Elterm rates this range for cascaded installations up to 1.5MW total output. Contact us for a tailored quote on multi-unit schemes.
What's the lead time on this product?
Typical lead time is 5–7 working days, as each unit is configured to order.
Can the boiler work alongside a heat pump or an existing gas boiler?
Yes. A volt-free switching contact lets the Battalion hand control to a second heat source when it's switched off, and take back over when it fires — making it well suited as a peak/backup source alongside an air source heat pump or as a bridge while awaiting a gas connection.
What electrical supply and protection does each output need?
All four models run on a 400V 3-phase supply. Protection ranges from 3 × 50A fuses with 5 × 16mm² cable on the 30kW unit up to 3 × 80A fuses with 5 × 25mm² cable on the 42kW and 48kW units — see the model comparison table above for the exact figures per model.
Does this need to be installed by a qualified electrician?
Yes. Electrical connection, commissioning and any work carried out with the casing removed must be done by a qualified electrician, and the installation must include adequate overcurrent and RCD protection.
