Water Heater taking 5 minutes to heat up

Hi,

Hoping someone can help me with this problem.

We have a 100Gal gas water heater and a recirculating pump installed when the house was built in 2001. It used to take about 10 sec for the water to get hot at the faucet. Recently it is taking 5 minutes before we get hot water at the tap, but once the water is hot, it stays hot and works fine.

I've checked the pump to make sure it was working, no obstructions in the piping as far as I can tell (no difference in water pressure from before). I tried to drain the water heater but seems like sediment/calcification has set in on the drain tap so water trickles out slowly. I've noticed that with hot water running it takes about 3 min for the water heater flames to turn on.

Why is the water heater taking so long to turn on?

Any ideas would be greatly appreciated.
Thanks.

The water heater won't start heating untill the cold incoming water lowers the water temperature in the tank to the thermostat cut on setting . Sounds like you have a problem with the circulation system . Maybe whatever is clogging the drain on your water heater has also clogged the circulation system .

Thanks WV,

I checked the circulating pump and also water pressure all over the house seems to be normal, so doesn't seem like a clog unless it is inside the water heater. Could it be a broken cold water dip tube?

My guess is that your pump isn't working anymore. The dip tube is fine if the water stays hot once it gets hot.

water

The pump could be defective. You could have a check valve that is stuck open OR closed at the pump. There could be an air bubble in the circulation pipe line. These are just for starters. The circulation line should be hot. If it is not it is not circulating. If it is hot, then hold onto the pipe while someone opens a hot water faucet. If it then gets cold you have back circulation.