Gas usage for Buderus G124X and IDHW

Drew Childress_2

I have a newly remodeled home in the Chicago area with a Buderus G124X boiler connected to a Buderus 53 gallon hot water tank. My gas bill is averaging over $200 per month this summer (3 therms a day). That is for two adults. The boiler and a gas cooktop are the only gas appliances in the house. The boiler also supplies a Unico air handler and two infloor loops but all of these are off. The boiler is set at 160 degrees.

Does this sound normal? I thought this was supposed to be a much more efficent system than the old gas water heater and forced air furnace it replaced. But last year we averaged less than 1 therm a day.

How do I troubleshoot? My installer doesn't want to take responsibility.

Thanks

Drew

Dale

Too High

3 therms a day is 300,000 btu. This is a 3 number increase in the rightmost( 1000 foot) recording dial on the gas meter. Unless you're using a phenominal amount of hot water there's a problem. I wonder what off means on the heating loops and unico. Are any of the pipes warm to the supposedly off areas. If there are manual valves shut them.If the pressure in the boiler isn't going over normat 12psi or so cold you problably don't have a leak in from the water heater loopl You have a gas meter that you can use to find out is there is any gas flowing when you don't expect it to. With the boiler and cooktop off look at the smaller capacity test dial on the meter for any movement, this should be a 1/4 or 1/2 foot dial. If the dial hand doesn't move in 5 minutes the system is tight enough. If it does move you have a leak, not all of which can be smelled. Is there a hot water leak? Look at the test dial on your water meter when you go to bed and before you use ANY water in the morning. If there's a change perhaps hot water is leaking somewhere. You may have some really bad single faucet mixing valves that are letting the hot and cold come in constant contact, you could be heating the city cold system and lake michigan. To test this turn the hot water heater cold water intake off and turn all faucets to hot, nothing should come out. With the water heater back on Turn the washer to cold fill and see if the inlet temp is the same as normal cold temp. The idea with a high bill complaint is to eliminate the most obvious stuff first. I looked at alot of esoteric stuff once only to find the kids had left the gas log lighter valve on with the fireplace doors closed and the gas just kept going up the tall chimney.

Drew Childress_2

Thanks for the troubleshooting tips. The loops for the air handler and in floor circuits are both cold. Also we used Aquapex for the water supplies with a home run to the basement. If a mixing valve was leaking I would feel it on the cold supply line. The plumber is stopping by today to look at the gas meter and check for leaks.

Also I called Buderus and was told to have the installer call them directly for guidance. He said the controls may be set wrong. Something about a "cold start stat" versus a "triple stat". One type of stat will try and maintain the boiler at a constant temp. This is bad as in the summer the boiler will fire more than it needs to and thus use a lot more gas. I told him it seems as if the boiler is firing several times a day even without hot water demand.

Drew Childress_2

I just talked to my installer. He says that I really need a Logamatic control for approximately $1,500. He is not a fan of cold start set ups as the G124X is not a condensing boiler and will get damaged even though that is what the Buderus technical support recommended.

Should I bite the bullet with Logamatic or take a chance with cold start?

Dale

I still think there's another problem

Let's say the boiler does maintain temp. Since you have a storage tank perhaps it needs 160 degree water, not being there I can't tell. I also don't know how much water is in your boiler.There is usually a differential so that it's on at 140 and off at 160 or so. Unless your basement is really cold why would the burner need to run so much. Remember that the old cheap water heaters sat in the same basements and with just a pilot light for input keep the water at 130. I would check this out much further before I strayed from the factory recommendations. As far as a cold start the tank is insulated which is where the majority of the heat is stored, the boilers have cold water return protection or the factory wouldn't provide the install instructions. I would look this one over before I spent money on more controls.

Joe_13

example of a clueless contractor

This story is a prime example of selling the customer a higher end product without knowing all the facts of how the technology works. What's the point of installing any high mass/water content boiler with an IDHW tank and just let it sit there with no boiler controls: just set the aquastat to 160? Without the controls, you probably would have been better off with a gas fired DHW tank. You could also look at 3rd party controls like Tekmar. I would get another contractor also since this one is just "discovering" what the options are.

Drew Childress_2

There is a separate enclosure which has honeywell controls. Of course there is no instructions on how to use it. I would love to have a credible second opinion on my set up. Are there any good wetheads in the NW suburbs of Chicago on this board? 99% of HVAC contractors in this area only do forced air.

Drew Childress_2

The boiler stat is set at 160 right now. I am going away for a long weekend and am going to turn off the boiler and check the tank temps and gas usage on my return Sunday.

Thanks

drew

Mark Hunt

Drew


Is there any chance that you have a gas leak some where?

It sounds like the boiler is maintaining temperature which is not necessary with the indirect tank.

Buderus boilers have no problem with cold start.

Mark H

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Glenn Harrison

N.W. Chicago suburban contractor

Drew, may I offer the services of myself and my employer. I'm a service tech for a major contractor in McHenry county, serving the entire Chicago area. Please feel free to contact the office at the number below, or e-mail me personally for any assistance that I can offer. By the way, we are a Buderus dealer, too.

Thank you.

Glenn Harrison, Residential Service Technician

Althoff Industries Inc.

8001 South Route 31

Crystal Lake, Illinois 60014

815-455-7000 or 800-225-2443

www.althoffind.com

personal e-mail - glennhvacman@msn.com