OSO HOTWATER Maxi Standard MS 300 User Manual (English)

Questions and Answers:

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aliciaphelpsAug 9, 2025
Why is there no hot water from my OSO HOTWATER Maxi Standard MS 300?
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  Erica MorganAug 9, 2025
  If you have no hot water from your OSO HOTWATER Boiler, first check if the fuse is on, the plug is properly connected, and the earth breaker hasn't tripped. If not, the thermostat may have cut out; in this case, press the ‘RESET’ button on the safety thermostat. A defective heating element or a leak in the hot water pipe could also be the cause. To check for a leak, close the water supply, wait 2-3 hours, and then feel the tank to see if it's still hot.
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harrisonheatherAug 14, 2025
How to increase the temperature of my OSO HOTWATER Maxi Standard MS 300 Boiler?
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  reyesdaleAug 14, 2025
  If your OSO HOTWATER Boiler isn't providing a high enough temperature, start by checking the thermostat settings and increase it to 75°C.
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Dean JacksonAug 19, 2025
What to do if my OSO HOTWATER Maxi Standard MS 300 is leaking from the safety valve?
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  marie23Aug 19, 2025
  If you notice leakage or dripping from the safety valve, or water on the floor near your OSO HOTWATER Boiler, it could be due to several reasons. The water pressure might be too high because of a faulty pressure reduction valve, water meter, or blocked non-return valve. In this case, fit an AX expansion vessel to absorb expansion during heating, and install a pressure reduction valve to maintain stable water pressure. Alternatively, the safety valve might be worn or have particles stuck in it due to dirty water. Try flushing the safety valve with water for about 1 minute. If the issue persists, the gasket or heating element may be leaking, which you can verify by cutting the power, unscrewing the cover, and visually inspecting for leaks.
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Alexander VaughanAug 25, 2025
Why does the fuse/earth breaker trip repeatedly with my OSO HOTWATER Maxi Standard MS 300 Boiler?
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  Angela MorrisAug 25, 2025
  If the fuse or earth breaker trips repeatedly when using your OSO HOTWATER Boiler, there might be a fault in the heater’s electrical system. To check, first cut off the electrical supply, then unscrew the cover and visually inspect the junction box for any issues.
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Nancy MooreAug 29, 2025
What causes knocking in pipes when closing hot tap of OSO HOTWATER Maxi Standard MS 300 Boiler?
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  powellleahAug 29, 2025
  If there's a knocking sound in the pipes when you close the hot tap with your OSO HOTWATER Boiler, it's likely due to a large pressure increase from the quick closing of the tap. This is generally normal, but you can install an AX expansion vessel if it becomes bothersome.
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oliverstevenSep 3, 2025
Why does it take so long for water to reach the tap from my OSO HOTWATER Maxi Standard MS 300 Boiler?
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  joshua09Sep 3, 2025
  If it takes a long time for the water to reach the tap from your OSO HOTWATER Boiler, it's likely due to a long stretch of pipe between the water heater and the tap.