Hello, all,

This might be a silly question, but I'm trying to make sure that I don't get conned tomorrow when the plumber comes back.

The Honeywell control valve/thermostat on my State Select water heater went bad: one day in the shower the water went cold, I checked the water heater after my cold shower, saw that the pilot light was off, and went hunting for my owners manual. I re-lit the pilot according to instructions, but the thermostat was blinking four times, and the Owner's Manual tells me that this means that high water temperature has activated the over heat sensor and I have to replace the control valve/thermostat.
No problem. I contacted State Select, and because the water heater was under warranty, they sent me a new thermostat. I'm not handy, and I don't want to mess around with anything that could be dangerous to me or my property, so I contacted a local plumber. I live in a small town that has only two plumbers, but when I called the first one, the number was disconnected...which means I have the choice of one plumber.

I told him over the phone yesterday that I just needed him to put in the new thermostat, and he came today. When he showed up, it wasn't too long before he told me that the thermostat wasn't the end of my problems and that the whole procedure would take a few hours. He started telling me about wires and that not enough air was getting in through the bottom vent (which is what he said actually caused the overheating in the first place even though the State Select guy during our emailed exchanges wrote that it's usually sediment in the tank that causes it). He even mentioned that he would have to drain the tank, which he made seem like a big deal, but I did that a few days ago (twice, after that email conversation with the State Select guy), and it did't take long at all and it was pretty easy.

I guess I made a face when he said hours and after I explained that I had gotten the pilot to relight but that I had shut down the whole system (thermostat and gas) when I saw it blinking the overheat code. He revised his time estimate to an hour for tomorrow, which gets us to my question:

If it does take an hour, how much should it run me? I've already got the part, and the instructions that came with the thermostat said that I only really need teflon tape and a few tools besides. It seems like I could do it in a few minutes, but, again, don't want to play around with dangerous stuff, so he should be able to handle it pretty quickly. I get, though, that he needs at least an hour to cover his costs, and, as a person who grew up poor and always had to work with his hands, I'm more than happy to pay him for that hour. But not any more than that if an hour is already plenty of time.

I'm also worried that he's going to try the same thing where he tries to add in additional problems/hours to what I need. Is it okay to just tell him to swap out the thermostats? I'm also worried that he's going to say that I HAVE to let him make some repair or else it could be dangerous (like I just saw in a bunch of YouTube videos that didn't teach me much but that sure freaked me out). I won't know enough to know if what he says is true.

Maybe another question is this: Would it be dangerous to have him just swap out the thermostats? I can't imagine what problems could develop or be exacerbated from from the thermostat swap.

I'll be honest and say that our ten-minute conversation today didn't fill me with a lot of confidence as to his ethics/business practices, but he's literally the only plumber in town.

Thanks, and sorry for the long post.