deactivate buderus hot water tank

**mtbmike** · 10-21-2010, 04:54 AM

Hi -
i have a 6 year old buderus oil fired boiler with a buderus hot water heater installed under it.
the hot water heater is broken and needs to be replaced. Warranty is not in effect because
the anode rod has never been changed. I'm not interested in replacing with buderus. considered
installing a superstor tank but price is holding me back.

I plan to install and use an electric hot water tank, and to try that for a few
years, maybe consider the superstor at that time.

my question is, will the buderus continue to run the boiler attempting to heat
water in the (now unused) hot water tank? What i mean is, presently the boiler
fires up whenever the hot water in the tank is depleted or cools down to some
preset temp. How can that be stopped?

**jadnashua** · 10-21-2010, 11:06 AM

It may be as simple as removing the leads from the aquastat for the indirect. If you have the model number and the manual, if it is possible without changing the controller, it should be called out. Often, an indirect is just another zone, so if you remove the ability of it to call for heat, it should stop any burn.

**mtbmike** · 10-22-2010, 05:13 AM

thanks for explaining that. sounds logical that that's what i need to do. i do have the manuals (Buderus G115 cast iron hot water boiler) and the aquastat (Honeywell L8148A) wiring schematic is in there. By comparing to the boiler schematic
i believe i can see the leads that need to be removed. i guess a little experimentation will tell!

Originally Posted by jadnashua

It may be as simple as removing the leads from the aquastat for the indirect. If you have the model number and the manual, if it is possible without changing the controller, it should be called out. Often, an indirect is just another zone, so if you remove the ability of it to call for heat, it should stop any burn.

**mtbmike** · 10-22-2010, 07:29 AM

Originally Posted by mtbmike

thanks for explaining that. sounds logical that that's what i need to do. i do have the manuals (Buderus G115 cast iron hot water boiler) and the aquastat (Honeywell L8148A) wiring schematic is in there. By comparing to the boiler schematic
i believe i can see the leads that need to be removed. i guess a little experimentation will tell!

ok, i have the honeywell i mentioned above, and it's connected to an Argo AR861 311 aquastat. the manual is here:
http://www.ecrinternational.com/secu...ument/1546.pdf

the circulator that contols my hot water is wired to terminals GZ2 and HZ2 on page 17. if i disconnect those
leads, does that make the boiler stop heating hot water? thanks for helping out this newby...

**jadnashua** · 10-22-2010, 09:26 AM

If someone that already knows doesn't answer, I'll look into it tonight. Got a few things that have to get done...

**Dana** · 10-22-2010, 10:55 AM

At Worcester's fairly high (Nat'l Grid) electricity costs, are you sure you really want to buy an electric tank, suffer it's lousy first-hour rating limitations while paying extra to heat it (slowly) up, then throw it all away in a couple of years?

Most (but not all) streets in Worcester are on the gas grid (NStar)- got gas? A bottom of the line gas tank heater would cost less to operate and deliver more HW than any electric tank in your (and my) utility environment, and will be be less than heating HW with the oil-fired Buderus too. We're at/under a buck/therm retail delivered price on gas, which would be the cost equivalent of $1.40 oil efficiencies all being equal. Summertime efficiency on the Buderus + Superstor would be somewhat less than a standalone gas-fired beast of a tank, but could edge it out during the heating season.

Only if yours is a hot-water sipping lo-volume household would an electric tank make any sense financially or operationally, but, not if you're just going to junk it in short years for something else.

**mtbmike** · 10-22-2010, 11:20 AM

ok, sorry, i'm not in worcester, i'm next town over (shrewsbury). No gas on my street.

**Dana** · 10-22-2010, 03:19 PM

Cheaper electricity in Shrewsbury too, if you're on the town grid as opposed to the Nat'lGrid served part.

**mtbmike** · 10-23-2010, 08:37 AM

we are on the town power grid.

also, as to my initial question - i'm all set now. Plumber simply disconnected the wire from aquastat
to the boiler, and no more call to heat the water. he's just left, waiting for electric tank to heat up now