I just had my water heater replaced by a plumber. Now the hot water flow and pressure is about 1/4th of what it used to be at the upstairs tub faucet. Other faucets in the same bath seem low as well but it is hard to tell. The bath tub faucet had great flow before and would fill the tub in 5 minutes. The plumber said he did not cause the problem but after talking to him more he said that the old water heater was plumbed backwards (cold water inlet was connected to the hot fitting on the heater and the hot water out let line was connected to the cold fitting on the heater). So I switched the hot and cold flex pipes around so they would be backward like it was before the water heater was replaced. Now I have great flow at the tub faucet but the hot water temp seems to cool off before the tub is full. Any help

Much appreciated.

Mike

This is perplexing since switching the lines should only cause the quicker drop in water temperature and not any change whatsoever in the flow rate. Put the lines back where they belong and lets start looking for ideas as to what is causing the problem. I would suggest you start by calling your plumber a second time and ask him if he did not cause the issue what does he think is happening. Stands to reason that if there was not flow problem, he did some work and now you have a flow problem, the plumber has some talking to do. Can you or he rig a tempoary by pass to test the house lines themselves for a flow problem. Ask the plumber tpo verify the water pressure before and after the new tank, should be the same, about 45 psi.

Hey Mike... somethings not right here!

First question: Gas or electric water heater.. Permit pulled.. Inspector showed up to inspect the water heater installation..

I have a couple ideas... let me know answers.. see what we can think of... Mark.

That one was a tie Bob... ;)

The heater has a dip tube on the cold water input side. Cold make up water is carried to the bottom of the tank to be heated. As water is heated the hot water rises to the top. Hot water is taken off the top. Hence the reason for the lack of hot water, you are taking the cold water off the bottom of the tank. Put the piping back to proper locations. The reversed piping affecting the flow is not logical unless something in the piping itself is changed by reversing, such a kink in the pipes.

Can you post a picture of the pipes?

Mark, that happens so often, we are both typing away thinking we are the only one there. I can't count the times I have hit enetr only to see you or Speedball1 were moments ahead of me. Looks like harold is only 6 minutes behind us so we better pick up the pace. Guess we all think this one is, as Spock would say, illogical.
Kokanee, I think we can skip the checking of the mixing valve which is kind of SOP for us since you say you have good pressure when the lines are reversed. Do you know or did you see that the dip tube was put in place?

I'm not slow, just waiting for you guys to put up the answer so I can copy it.

I just had my water heater replaced by a plumber. Now the hot water flow and presure is about 1/4th of what it used to be at the upstairs tub faucet. Other faucets in the same bath seem low aswell but it is hard to tell. The bath tub faucet had great flow before and would fill the tub in 5 minutes. The plumber said he did not cause the problem but after talking to him more he said that the old water heater was plumbed backwards (cold water inlet was connected to the hot fitting on the heater and the hot water out let line was connected to the cold fitting on the heater). So I switched the hot and cold flex pipes around so they would be backward like it was before the water heater was replaced. Now I have great flow at the tub faucet but the hot water temp seems to cool off before the tub is full. Any help

Much appreciated.

Mike
Thanks guys for your input. I had a Manager from the water heater company out today and he found that some thermo valve in the water heater inlet and outlets were installed opposite. Cold valve was in the hot and hot in the cold. I do not remember his exact name for the valves just that he says they help stop heat from being lost through pipes when there is no water flow. Any way I now have great flow with the heater lines connected properly. Make any sense? Mike