Elevate your home's heating efficiency with the Vaillant Thermo Hydrometer, a genuine part designed to deliver precise measurements for your boiler's performance. With part number 101558, this essential tool ensures your storage tank water heater operates at its best, allowing you to enjoy consistent hot water and a warm indoor environment. Crafted in the United Kingdom, this component is tailored for indoor mounting locations and boasts a sleek black finish that complements any home decor. It's an ideal choice for those who value reliability and quality, ensuring your heating system runs smoothly without compromise.