Zilmet 539 OEM-PRO 8 Liter M14 Rectangular Combi Boiler Expansion Vessel – Baymak Novadens, Baxi, Westen Compatible

This is the Zilmet equivalent of the 8-liter rectangular expansion vessel with M14 connection used in Baymak Novadens, Baxi, Westen, Chappee, Lambert and Falke combi boilers. Part of the Italian brand Zilmet’s OEM-PRO series with drawing number 539, this vessel absorbs the expansion of heated system water, balancing system pressure and preventing the safety relief valve from opening unnecessarily. Its rectangular (flat) body shape is designed for models where it sits horizontally inside the boiler casing.

Original Zilmet Vessel Compatible with Baymak Novadens, Baxi, Westen, Chappee, Lambert and Falke Boilers

• Brand / Series: Zilmet / Drawing 539 – Family 13S OEM-PRO
• Yedepa Product Code: ZLM106
• Nominal Volume: 8 liters
• Connection: M14 thread (installation inside the boiler)
• Body Shape: Rectangular (flat) steel body, red baked paint
• Maximum Working Pressure (P max): 3 bar
• Pre-charge Pressure (Precharge): 1 bar
• Maximum Operating Temperature (T max): 90°C
• Other: Pre-charge check valve (Schrader valve) on top, for closed-circuit heating systems

Zilmet 539-8 (Family 13S OEM-PRO) Technical Specifications and Installation Warnings

• Not for use in drinking water installations. As also stated on the product label, this vessel is for closed-circuit heating systems; do not fit it to a booster pump or potable water line.
• Measure the pre-charge pressure before installation. The vessel comes with a 1 bar pre-charge; if the system fill pressure is different, adjust it at the valve. Measurement and adjustment must always be done with the water side of the vessel empty.
• For membrane life, a pre-charge check every six months is recommended. If the pressure keeps dropping or water comes out of the valve instead of air, the membrane is punctured and the vessel must be replaced.
• Shape and size check: Vessels of the same volume are produced in different body shapes (round/rectangular). Before ordering, compare the shape, connection size (M14) and position in the boiler casing of the vessel you will remove.
• Do not strain the vessel body when tightening the M14 fitting, do not skip replacing the seal, and check for leaks after installation with the system under pressure.
• When installing inside the boiler, refit the anti-vibration pads; metal-to-metal contact causes both noise and, in the long term, fatigue cracking.