How does an immersion heater refill with water?
Hi, recently moved into a rental property with a 125L unvented water tank with 2 immersion heaters. No gas boiler. No economy 7. The lower immersion heater is hooked up to a timer switch.
From what I understand on google only the lower heater will turn on based on the timer switch and the upper heater will run when I manually set the heater to "boost" if I run out of hot water during the day.
So how fast is used hot water replenished in the tank? If I heat a full tank of hot water in the morning, and say I use only half of it during the day, is the tank now half empty until it fully empties or does it get topped up with cold water right away? I want to say surely not because that would immediately drop the temperature of the other half of the hot water and it would be inefficient right? So when does the tank refill?
Advice from 1 local tradesperson
Your direct unvented cylinder will replenish with cold mains supplied cold water the moment you open any hot outlet tap or valve connected to the system. In simple terms, any cold water introduced to the cylinder will reduce the temperature of the water but hot the cylinder will still hold hotwater at a certain level until it has been consumed.
Please bear in mind that depending on your usage, the immersion heater timings and the time the hot water takes to re generate in accordance to the manufacturers instructions the immersion thermostats should automatically start the heating process ( call for heat) once it has detected that the tempreture has dropped below the desired level. The volume of hot water used will ultimately affect the timing of your immersion heaters.
