As a standard immersion heater is 3KW, so it would take 2 hours to heat 100 Litres of water. After an hour and a half, it will only have reached about 53 degrees.....
Another common cause of heel and calf pain is Achilles Tendinitis. Symptoms are frequently described as an aching pain in the back of the lower leg and just above the heel. This sensation is typically worse after exercise and upon first waking up in the morning.
Heel pain is not usually caused by a single injury, such as a twist or fall, but rather the result of repetitive stress and pounding of the heel. Common causes of heel pain include: A heel pain sufferer commonly feels pain either under the heel (plantar fasciitis) or just behind it (Achilles tendinitis).