I Want New Water Heater

I think I have to request my hubby to buy a new water heater to replace the one that having problem. I think the old water heater going to out of service soon, because sometimes it is ok but sometimes it do not supply hot water at all. I saw the new tankless water heaters available in the market, but I am not sure my hubby would know how to install it. Anyway, I will ask him if he knows how to install then I probably will ask him get the new one.