Domestic Hot Water from Boiler Question

Guy_6

The fact that the knob was stripped is indicative of the shaft being corroded to the point of immovability. If the water has done that, it would not surprise me if the thermostatic shaft in the mixing valve is either seized or sticking.

You are in good hands with Kevin.

Guy
Mestek/ Smith Boiler

P.S. Thanks for showing that the boiler is a Smith. That Series 8 is a great piece of equipment, and although they are heavy going down into a basement, extremely few ever have to come UP out of the basement.

Peter Means

Hope this isn't too off topic

I've drawn out the domestic hot water system I have inherited (below, I do illustartions for my work). I'm a homeowner who has been on this site quite a bit for the steam stuff, and now for the second time in the last 2 weeks my hot water has had problems. Hope I'm not too off topic.

It had been working fine before this, for about 2 years when we moved in. What happens is the water goes from hot to warm over a few hours and then just stays warmish, even when left overnight, with no usage.

I've been able to get it back working by doing a few things, but I really don't know which thing makes it work again, and I'm sure it'll do it again, so it needs attention. What I do is: 1. tap the Taco box, 2. tap the pump, 3 turn the temperature adjustment on the boiler down and up a bit.

The last thing seems to make the boiler fire, but not every time I turn it up. After doing these things, I'll check the hot water at the tap and find it's back up and hot after about 30 minutes, or so.

One other thing I've noticed is that the pipe on the right going to the boiler his quite hot and the one on the left is room temp. when the hot water is not working. When the hot water is working, it's the opposite. ????

So my questions are:

1. What might be shot?

2. How does this system work in a nutshell?

3. Is the piping looking fairly correct? After being on this site and reading Dan's books, I've found most of my steam boiler piping to be wrong, and I wouldn't doubt if much of this is screwy too.

Thanks in advance. Knowing this question is off topic, I'll put a brick in the wall for your advice. --Peter

don_182

maybe

a springcheck after the circ and before the t on the hot water line, would do the trick.

Opps forgot to ask..mixing valve, do they not have to be trap in some way to keep them from hunting?

Unknown

Peter,

That`s a really great drawing! And I agree with don on the check-valves and "trap" on the mixing valve issue. If it worked for 2 years before, and its actually mounted this way(mixer), then the thermostatic element inside is likely "euchred" now. The check valves will keep the water circulated to the boiler`s coil separate from the cold tank inlet when your "drawing-it" off.

Guy_6

mixing valve

I would suspect the mixing valve, as they are more likely to give you an occasional failure. If the pump or relay were failing, they usually fail and stay failed.

Does the hot water occasionally start off hot , then drop to luke warm within a minute or so?

Peter Means_2

mixing valve

Guy, I've not really noticed how quick the transition from hot to luke warm is, so it could be minute, but not sure.

About a month ago I had Kevin Coppinger (on here quite a bit, found him from find a pro.) look at a few steam heat items here, and in the process, talk turned to the hot water, and he found the plastic adjustment knob on the mixer was stripped. The hot was really hot and we were trying to get it down. Later, I removed the plastic knob, and was able to get to a wrench on the metal nut beneath it, which turned just fine and I got the water at the taps down to 120. This was about 2 weeks before the problems began.

So maybe there was a reason the knob was stripped, perhaps it really needs replacing. Either that or is it possible that adjusting it one way or the other too far could make it work incorrectly? Without the plastic knob on there, perhaps I turned it too far one way or the other.

If I need to replace, Kevin I'll be giving you a call if you are reading this. --Peter

Peter Means_2

Knob

Thanks for your help Guy.

My apologies for not having reproduced the Smith logo to exact specifications! lol, That was the closest font I had. And I took the liberty of moving your logo from the front of the boiler to the side. Both of these are serious copyright infridgements, I'm sure. On that note, I hope you all can over look the fact that I didn't include the wire ties that hold the wires in place!

Seriously though, I like the boiler as well, but mostly because it is red! Okay serious again... Seems the burner servicing guy has been using a smaller burner nozzle on it. Kevin thought that seemed a bit odd. I don't know if that's to underpower it? Think it might be too big for my load. Hopefully that guy (the boilder service guy) knows what he's doing and why. The boiler seems to work great, as far as I know.

Of course the thing was piped all wrong, but that's another thread, and another illustration, for another day.

--Peter

Unknown

You can't go wrong

with Kevin working on the system . I would guess it's the mixer valve . Another thing to check is the circulator . What brand and model number is it ? And can you tell us which direction it's pumping ? If it's pulling water from the coil , that means it gets hit with the hottest water all the time . That might deteriorate the impeller faster than normal . Also , I don't like how one of the coil pipes are teed in right below the mixer valve . I'd rather see the hot outlet of the heater going right into the hot of the mixer by itself ( although I'm not sure exactly how that would affect the mixer , I'm guessing it does affect it with the circulator running ).

And I agree , that's some snazzy diagrams Peter .

Al Corelli

That drawing is beautiful!

You even got the right shade of red for the Smith 8.

Never had any problem with a Smith 8. We have many of them out there.

Peter Means

Photos

I'm learning... What I showed in the diagram as a little vertical pipe, before the mixer, seems to be a check valve! Here's a bunch of photos that show it all better (below).

So the circulator is on the hot side. When we have hot water, the pipe on the left (with the circulator) is hot and the pipe on the right is cold. When it's not working the pipe on the right is hot, and is hot all the way to the base of the water tank, and the pipe on the left with the ciculator is only room temp.

Whatever it is. It's a job for Kevin. Thanks everyone and I'm off to put a brick in the wall.--Peter

Alan_11

checck wiring

If this is wired so that the tank aquastat starts the circulator using the low voltage wire to pull in the relay the wire from the breakers should have no use. Looks like an electric water heater converted to a storage tank.no need for juice to the electric elements. If wired properly , turning the tank aquastat up and down should start and stop the pump.