No heat on boiler. Boiler was showing e04 code. This code means there was an interruption of power during a heat call. I reset the boiler. It is heating now. He expansion tank is leaking and needs to be replaced. I also recommend having maintenance done to the boiler, furnace and air conditioner. Average life of high efficiency boilers is 10-15 years. Office will call when we have the expansion tank. Office will call to schedule maintenance. We will send a bill. I drained water out of the piping. I removed the leaking expansion tank. I installed a new expansion tank. I purged air from the piping. I cycled the system. The boiler is heating now and there are no water leaks.