Why is my Megaflo not heating up?

Why is my Megaflo not heating up?

Lack of hot water – this fault could relate to either an electrical fault or an issue with an immersion heater. Low rates of water flow – could either be a fault with the pressure reduction valve or the fact that the filter in the pressure reduction valve has not been cleaned.

What temperature should Megaflo be?

Safety Precautions of an Unvented Megaflo System: The ideal temperature for a cylinder is usually between 60 to 65° Celsius, which tends to be the default setting for the controls.

How do I reset my Megaflo?

How do I regenerate the airgap on my Megaflo?

  1. Turn off the mains cold water supply to the Megaflo.
  2. Open the lowest hot tap in the property.
  3. Hold open the temperature / pressure relief valve until the gurgling noise stops and water stops running from the tap and valve.

How do you service Megaflo?


  1. Partially drain cylinder.
  2. Recharge air gap.
  3. Replenish water supplies.
  4. Check condition of safety valves.
  5. Check test electrical connections.
  6. Check operation of zone valve (CL models only)
  7. Check resistance of immersion heaters (DD models only)
  8. Check continuity and operation of thermostats (DD models only)

How long does a Megaflow take to heat up?

Should have added that it takes ~30 mins to reheat from the boiler, or ~20 mins if the immersion heater is on as well.

What pressure should my Megaflow be?

about 3 bar
Megaflo – an unvented hot water cylinder The actual pressure in this type of hot water cylinder is normally about 3 bar, which is equivalent to a cold water tank being 30m above the tap for a heat-only system. The cold water is fed into the bottom of the tank at mains pressure.

Should Megaflo unvented cylinder hot water setting be on constant or on timer?

The hot water inside should stay hot for a long time, without the need for the boiler (or immersion heater) to fire up. The risk to put the cylinder on timer, would be the lack of hot water, when three or more people take shower one after another.

What temperature should my unvented cylinder be?

A domestic hot water cylinder thermostat should be set at 60-65ºC. This is high enough to kill off harmful bacteria such as Legionella. If you set the thermostat much higher than this the water that comes out of the taps will be too hot and there’ll be a risk of scalding.

Where is the reset button on a hot water tank?

Somewhere on your electric water heater, you’ll find a reset button. It’s usually red and often located near the thermostat. It may also be hidden behind a removable metal panel on the unit—and then behind some insulation. Once you find the button, push and release it.

How often should you recharge a Megaflow?

Drain it down and refill it to recharge the internal airgap. Plan on doing this at regular intervals (Megaflow recommend every 4-6 months) to avoid the gap getting small enough to cause the valves to lift.