Biasi boilers
Biasi is an Italian company. Leopoldo Biasi started a small heating business in 1938. In the 1940s he opened a factory to make boilers for homes, and gas boilers followed in 1986. Biasi boilers are made in Pordenone, Italy. Biasi says they’re sold in at least 40 countries.
Biasi UK Ltd was set up in 1990, and it works from a large site in Walsall in the Midlands. It also sells radiators and towel rails, and runs a training centre for installers.
The Biasi range
Biasi’s UK website lists these gas boilers:
- RinNova Adaptive, a combi in 25, 30 and 35 kW sizes;
- Dina, as the Dina 24S and Dina 32S;
- Antares, which comes as a combi or a system boiler;
- Inovia Tec.
Older Biasi boilers include the RinNova Tec, Inovia, Advance Plus, Riva and Basica Cond. Biasi keeps manuals for many of them on its documents page. Biasi says it keeps spare parts for 12 years and beyond. The usual industry figure is 8.
Need the serial number? On Riva boilers it’s under the drop-down flap. On the Inovia and Advance Plus, look for a small grey sticker on the front. The number starts with N. The last four digits show the month and year the boiler was made.
How Biasi boilers show a fault
On a RinNova Adaptive, a fault shows as an E and a number. A symbol appears with it, and that symbol matters.
- E with the b symbol is a lockout you can reset. Press the reset button on the boiler.
- E with the A symbol is a fault you can’t reset. Call a Gas Safe engineer.
After three resets in a row, the boiler shows E91 and locks out fully. The manual explains a special restart for this. It means switching the power off and on, then holding three buttons together. If you have to do that, the boiler needs checking.
Biasi’s manual also says a blocked condensate pipe can cause a lockout. In winter, check for ice. Here’s how to thaw a frozen condensate pipe.
A spanner symbol on its own isn’t a fault. It means the boiler is due a service.
Pressure
Biasi says the pressure should be 1 to 1.5 bar when the system is cold. The screen shows it as a number, so “13” means 1.3 bar. The boiler will still run above 0.3 bar.
If water drips from the pressure relief valve, check the gauge. It may be close to 3 bar. Biasi says to let some water out by bleeding a radiator. If you keep having to top up, Biasi says something is wrong. Call a heating engineer. Our guide shows how to top up low boiler pressure.
Frost protection
Biasi boilers protect themselves in cold weather. If the boiler gets below 5°C, it fires up to warm itself. So Biasi says not to drain your system when you go away. Leave the boiler on standby instead.
Biasi gas boiler ranges
These are the gas boiler ranges on the Biasi website as of 21/10/2026.
- RinNova Adaptive Combi
- Dina
- Antares CombiSystem
- Inovia Tec
Older Biasi ranges
You may still find these in homes. They are no longer sold new, but many are still working.
- RinNova Tec
- Inovia
- Advance Plus
- Riva
- Basica Cond
Common Biasi fault codes
Codes can differ between models and ages of boiler. Always check the user manual for your exact model.
| Code | What it means | What you can do |
|---|---|---|
E01 | Safety lockout. The boiler failed to light. | Check your gas supply and any prepayment meter. Check the condensate pipe isn't blocked or frozen. Then press reset. |
E02 | Lockout. The safety thermostat has tripped. | Press reset once. If it comes back, call a Gas Safe engineer. |
E04 | Water isn't circulating. The pressure may be too low, or the pressure sensor isn't connected. | Check the gauge and top up to 1 to 1.5 bar. If the code stays, call an engineer. |
E91 | The boiler has been reset too many times and has locked out. | Follow the restart steps in your user manual. If it locks out again, call an engineer. |
L1 | The hot water heat exchanger can't pass on all the heat. It may be clogged with limescale. | Call a Gas Safe engineer. |
Biasi manuals
Biasi puts its user guides and installation manuals on its own website. You can find Biasi manuals here. You'll need your model name. The GC number helps too. Our guide shows you how to find your boiler's model and GC number.
Stay safe. You can reset a boiler, top up its pressure and thaw a frozen condensate pipe yourself. Anything inside the case is a job for a Gas Safe registered engineer.
If you smell gas, leave the building and call 0800 111 999.