warm house... cold water

With my Hitzer insert, the oil burner never needs to come on for heat. Since the burner has a coil for heating domestic hot water, and with the temp of the water coming into the house so low in the winter, I am not raising the water to a comfortable temperature to take a shower even if I force the burner on ½ hour before I shower. So I need to change something. The mixing valve in off so no cold water is added after the water is heated and the burner is set for Hi 160 Lo 140 with a diff of 15. I hate to have to burn more oil in the burner just for hot water, that doesn't sound efficient, but maybe better than changing to electric (we got high rates in CT) or something else to get hot water. Has anyone else faced this problem?

Bump the aquastat to 180/160 with a 10 degree differential.

I'm smelling a mouse.... I'll bet the coil is clogged & needs an acid flush. If the boiler is at 160 & you're not getting hot water, something is wrong. Is the flow slow?

I have good water pressure, I have to keep the hot water valve in the shower just cracked to slow the rate down so not to use up all the hot water. Cold water isn't even turned on. The burner is just below the bathrooms so I cant be loosing that much heat from the pipe run.

It is a waste and a shame to use the "summer-winter" hookup to heat domestic hot water, even if you were using boiler for heating. You would be better served to use a dedicated source for domestic hot water. If you have a basement, consider a heat pump water heater,expensive to buy, but will use less than 1/4 of the electric. A resistance unit costs about the same to operate as a boiler at $4.00 gal.

homecomfort wrote:It is a waste and a shame to use the "summer-winter" hookup to heat domestic hot water, even if you were using boiler for heating. You would be better served to use a dedicated source for domestic hot water. If you have a basement, consider a heat pump water heater,expensive to buy, but will use less than 1/4 of the electric. A resistance unit costs about the same to operate as a boiler at $4.00 gal.

Not sure what you base that opinion on but I could not disagree more. My domestic water coil which is in my oil boiler has a very minimal effect on the coal boilers temperature and saves my a bunch. I'm sending the output from my coal boiler through the oil boiler. My well water is always about 50*. So it's a helluva lot more cost effective than dumping 50* water into an electric water heater.
I agree a heat pump water heater is a nice way to go but I've already got one mortgage. I don't want a second one.

You are a Connecticut Yankee, I KNOW you will opt out of the heat pump option, and perhaps you are ready for another coal burning option.

Don't know anything about your home and heating needs, but I will bring up two word for you to consider: stoker boiler.
Heating hot water with a domestic coil is done every day by the millions of homes, and I for one prefer an indirect simply because you can use it with any heat source. If you were happy with output previously, then start by doing the acid bath and see if that resolves the problem. If not look at replacing the coil. It is short money for now, however I suggest you do more reading about central heating solutions. PM me if you would like and I'll offer my .02.
I know if there are women in your household, the 'warm water issue' will facilitate you building a spare room on the 'dog house'.

If this is the first winter you have heated with coal, it is probably the first time you have relied purely on the aquastat's low limit to control the boiler temperature. When the boiler is often running to heat the house, it is probably 150-160 degrees. Perhaps the coil does need to be cleaned, and maybe the mixing valve is suspect as well...but if you want to get by until warmer weather I suggest bumping the aquastat to 160/180 or even a little more...it won't cost you anything to try, and you won't have to shut the system down.

Have someone run the hot water and feel the pipes before and after the mixing valve. If the pipe coming out of the boiler is significantly hotter than the pipe after the mixing valve, you have found the problem. It is very common for these to fail, particularly if you have untreated well water. Some models can be taken apart and cleaned with CLR, vinegar or citric acid. Basically, salts build up on the parts and they can't move to properly adjust the water temperature.

Mixing valve pipe out of boiler I cant touch its too hot... after the valve i can grasp it tight with the valve off. SO first thing is to pull that apart. Thanks guys

I took the mixing valve apart and cleaned it as Coaledsweat suggested. It looked OK but i cleaned it anyway since it was off. After reinstalling it there was a slight improvement but not much... or maybe I just wanted to believe it was better.

Freddy's comment about if the boiler is set for 160 i should get hot water kept bugging me. I had talked to my furnace company and also a plumber previously and nobody told me that and neither suggested the mixing valve might be a problem.

So I found a repair kit for the valve on-line which contained a spring, washer, and some bi-metal do-hickey and replaced the old parts. Suddenly HOT WATER!!! Now I have to turn the aquastat back down and open the mixing valve a bit as well.

My coal insert made me search out this website which now has saved me big bucks in NOT having a plumber come out and install an indirect hot water heater....I am saving in ways I never imagined!

Many thanks to all who responded

coalkirk wrote:

homecomfort wrote:It is a waste and a shame to use the "summer-winter" hookup to heat domestic hot water, even if you were using boiler for heating. You would be better served to use a dedicated source for domestic hot water. If you have a basement, consider a heat pump water heater,expensive to buy, but will use less than 1/4 of the electric. A resistance unit costs about the same to operate as a boiler at $4.00 gal.

Not sure what you base that opinion on but I could not disagree more. My domestic water coil which is in my oil boiler has a very minimal effect on the coal boilers temperature and saves my a bunch. I'm sending the output from my coal boiler through the oil boiler. My well water is always about 50*. So it's a helluva lot more cost effective than dumping 50* water into an electric water heater.
I agree a heat pump water heater is a nice way to go but I've already got one mortgage. I don't want a second one.

Been in this biz. for 20 yrs, well known industry comparison. my mortgage was much more than my h/p water heater, and has paid for itself already. summer/ winter is about the worst in overall efficiency.

Ctyankee wrote:..........
So I found a repair kit for the valve on-line which contained a spring, washer, and some bi-metal do-hickey and replaced the old parts. Suddenly HOT WATER!!! Now I have to turn the aquastat back down and open the mixing valve a bit as well.
......

I remember the oil boiler at my parent's house having one of those when I was growing up. We had the same problem, so dad eliminated it.

After that, you had to watch out! It went like this: Turn on hot water, get ice cold water for 5 seconds, then sear your skin off with 220° water .. and if you let it run too fast, lukewarm water.

They JUST replaced that same boiler just 2 years ago! You had to take showers with the water trickling ... otherwise you'd run out of hot water. My parent's dealt with that for 3 decades ....

Some details not mentioned in this thread...

As for mixing valves, do NOT turn off or throttle the cold water input in hopes to gain increased hot water temperature output.
And always pipe the mixing valve w/ a Heat Trap coming from the hot input source.

Some or all of this probably was the cause for ruining it.

McGiever wrote:Some details not mentioned in this thread...

As for mixing valves, do NOT turn off or throttle the cold water input in hopes to gain increased hot water temperature output.
And always pipe the mixing valve w/ a Heat Trap coming from the hot input source.

Some or all of this probably was the cause for ruining it.

Just ran down and checked the cold water intake... it was open Thanks for the tip.
Now I been thinking, since I only used the hot water when I shower in the morning b4 work, would it be cost effective to have the oil burner run on a timer so it is shut off for most of the day? Is there a problem with doing something like this?