We just moved back to our own property which was rented out before. Just found out that there is some problem with hot water. When we have a shower, we turn it on, the first 20 seconds it is working fine, hot water with high volume. After around 20 seconds, the water turns to cold. In order to keep it warm, we have to turn up the hot water to the maximum and turn down the cold water, then we can still have a shower, but the water volume is very very low.
We have a gas boiler Potterton Suprima on the ground floor and Santon Premier Unvented hot water cylinder on the top floor. At the beginning of April, the tenants told me that there was no hot water and central heating, we have a plumber to repair it . The plumber has changed a pump, which has costs me £300.00. I don't know whether it's related to the changed pump. I don't know whether I shall contact the plumber again. Because last time, when he changed the pump, he didn't turn off the radiator tight enough and the water was coming out from it, and the tenants did not tell us about it. When we moved back and found out, we bought the radiator key to turn it off , while it was too fragile and it's broken.
Anyone knows any solutions?
Thank you!