Superstor contender piping ?

wrxz24

The hot water pipe was warm about 2 feet up

And the cold fill pipe was luke warm about 2-3 feet up. Temp of tank was 134 and calling. The indirect has run 4 hrs total the last 30 hrs.....

icesailor

Asking too much:

I almost think that you are expecting too much from what you have. Something sounds OK to me but from a theoretical standpoint, it appears to be off. When in real world situations, its OK.

I'd still buy a three speed circulator that has a higher output than the 007. Then run it on the highest speed and see if its different. Running 4 hours in 30 hours doesn't sound excessive to ma. But I'm not there.

Someone brought up DHW Cross contamination. I'd be looking at that. I've seen it in a lot of cases. Especially with older Moen shower valves where the balancing spool is outside of the on-off cartridge or shower valves with Check Stops.

You mentioned something about a long run to the indirect in the garage. Most of us will assume that the indirect is next to the boiler/heat source. A long run from the boiler to the indirect will loose energy and be a reason to go with the 1" piping.

Remember about resistance and pipe size. A smaller pipe has more resistance than a bigger pipe because there is more wall resistance in the smaller pipe. But "Pipes increase as do their squares" which means that it takes 4-3/4" pipes to equal a 1 1/2" pipe, and it takes 4-1" pipes to equal a 2" pipe. Consequently, it takes 2-1/2: pipes to equal a 1" pipe.

The long run pipes need to be insulated. They act as heat convectors.

wrxz24

Run time for dhw since May is

780 hrs. 7000 plus ignitions. I have to try with new pump and piping. Will let ypu guys know after completed.



Thanks for all the help and ideas.



Pete

wrxz24

The indirect is about 5 feet from the boiler

so there is  not a long run.  There are a few 90's on both supply and return piping so that will add to the resistance.  I am still confused about how to pipe it. One manual says to pipe the supply from the boiler to the higher tapping of the coil with the circulator.  Another manual says to put the circulator on the return.



There is about 20 feet of pipe for the hot water to travel before getting into the 68deg heated house.  I will insulate the pipes at the same time.

Zman

Siggy

John  Siegenthaler always specifies the boiler supply to the top and return on the bottom of the indirect. It has something to do with counterflow, I honestly can't remember the reasoning at the moment. When in doubt, do it Siggy's way.

Have you checked the positioning of the sensor in the tank?

Carl

wrxz24

i will do it ziggys way

The sensor enters through the opening where the old indirect thermostat went.  So I assume it is near the bottom of the tank.



I watched the boiler tonight to see how long it took the indirect to go up 2 degrees.  From 132 -134 took about 5 minutes or so and had 190 deg water going to and 168 coming back.  The DHW ran 2 hrs today from 5 this morning until 4:30 this afternoon.  2 showers. 



What do you recommend for a differential setting?



I just ordered all the stuff to make it 1 inch and the 15-58 pump.  So I will update you guys when I get er' done.  I may swap out the pump first to see if that improves things for the time being. 

Alan (California Radiant) Forbes

Please do.

I'm on pins and needles for an answer to the disappearing BTU's.

M Lane

BTW

It is piped right if you were in the Southern Hemisphere, I think.

M Lane

BTW

It is piped right if you were in the Southern Hemisphere, I think.

wrxz24

Unfortunately

I am not in the southern hemisphere

wrxz24

I will let you guys know

When i change out the pump and see if that makes a difference then i will change the piping to 1".

icesailor

???

You said something like this before.



>>The DHW ran 2 hrs today from 5 this morning until 4:30 this afternoon.  2 showers. 

wrxz24

The sensor is about 12 inches above the bottom of the tank

In the same location as the thermostat was originally. They used foil tape and then spray foam. However there was a 3x3 section that did not have spray so the tank was exposed to the air near an outside wall. Above the spray foam, there was another small section exposed. Not sure how much of an affect that would have on heat loss.

The boiler ran an additional 2 hrs last night while we were sleeping so the tank dropped 8 degrees at least one time or maybe 2 or more....not sure. Could it be due to that small section of tank without insulation. I packed it full of aluminum foil insulation board and screwed the cover back on.

RobG

IR Thermometer

Do you have an IR thermometer to verify the supply and return water temps? Right now you are trusting the boilers sensors. I would check that before I re-piped the system. You never know, all it takes is one bad sensor to spoil the whole barrel.

Rob

wrxz24

So far i changed the pump and

My first observation is that when I went out to check the temp of the tank, it read 142. It has never been that high before. It is set for 138. Not sure if that is the result of the garage being warmer due to warmer weather or the pump.



I did not get a chance to see how it recovers yet as I had to leave the house today after taking a shower.



The pump 15/58 is on speed 3. Will keep observing.

wrxz24

Thread bump.

I finally got around to repiping the ihw heater to 1 inch and having the supply enter the upper tapping and the return leaving the lower one.

The 15 58 is set to speed 3. I have noticed that it does in fact recover faster but it is still cycling on and off a few times during the recovery time.

My next step is to replace the anode rod and pour about 5 gallons of cleaning vinegar in it to clean any of the buildup that may be on the coil.

SWEI

Did you have a chance to adjust the DHW differential in the boiler controls? I find raising those to be quite helpful (as long as an ASSE 1017 mixing valve is installed.)

wrxz24

No, but it is set for 4 degrees. My temp setting is 134. No mixing valve but am considering it.

SWEI

Well that explains your short cycling! We use a 14-16˚F differential whenever possible.

Docfletcher

Zman not very long ago gave me some very good information when I was just about to install my SS35 contender. You can read the thread here.

http://forum.heatinghelp.com/discussion/151407/indirect-water-heater-swap#latest

I plumbed mine with 1" copper except where the pipe met the ball valves at the boiler mains. There it was necessary to reduce to 3/4.

Supply out of the boiler went to the top (supply in) inlet of the superstor. Then out the bottom (return) back to the boiler.

Recovery is very fast, 10 to 15 mins at the most. My boiler output BTU is 88000. Usually even faster than that.

wrxz24

SWEI said:

Well that explains your short cycling! We use a 14-16˚F differential whenever possible.

I watched this morning after my shower, the temp in the tank was 100 deg, 34 degrees less than the setting and it still reached the set point.

I have about 20' total of pipe and about 6 elbows that connects the ssc 50 contender to the boiler.

How would setting the differential to 14 degrees help?

SWEI

Larger differentials dramatically reduce short cycling, but they generally mean raising the DHW target temp, which pretty much demands a mixing valve. They can also cause increased recovery times, so if the tank is already on the small side they may not make for happy customers.

wrxz24

I think a mixing valve will be next.
I am still confused about the boiler no being able to recover the tank on one complete burn cycle??
The only other thing it could be is the heat transfer is not getting through the coil that is built up around the coil.

wrxz24

Update. So I took out what was left of the anode rod, about 18 inches, and drained about 20 gallons of water. Looked in the opening and saw that there was a white coating of scale around the coil.
Poured in 10 gallons of cleaning vinegar and am letting it sit most of the day.

Bought a replacement anode rod but have to reduce the opening from the water tank from 1 1/4 to 3/4 so it will fit.

Will see if this makes a difference in recovery times.

kevink1955

I have a Bradford 75 gal indirect that has 2 coils, The installation manual wants the supply in the top taping and the return at the bottom.

Since I only have the boiler as the heat source (the second coil was intended for solar) I piped the boiler supply to the top of the uppermost coil then came out of the coil and into the bottom of the lower coil the return is on the bottom 1/3 of the tank.

My thinking was heat the top of the tank first for fast recovery then heat from the bottom where the water is coldest, That's the way electric water heaters do it, heat the top first then switch to the bottom element.

I can almost empty the tank with my jetted tub, recovery to shutoff at 130 is around 30 min with around 170 boiler water, Boiler is a cast iron Peerless 100,000 BTU and piping is 3/4" using a 007 and zone valves.

With moderate HW use it only fires the boiler 1 time a day till someone showers or I fill the tub. Boiler on time on all except a tub fill is around 20 min.

I love this thing

wrxz24

Great news guys, btw thanks for all of your help.

The piping is fixed from 3/4 to 1 inch, new pump, and now a clean coil.

There was much more lime/ crud around the coil than I thought. The coil looked like a foam noodle size.

No wonder my recovery was so slow and the boiler cycled.
The boiler has now recovered from 50 degrees to 134 degrees in one burn and did not take very long.

Should of done this last year. Would of saved some wear and tear on the boiler and my wallet!!


Thanks again guys!!

wrxz24

What a breath of fresh air. The time it took to recover from 118 deg to 134 took only 8 minutes and just 1 burn/cycle!!

Thanks again guys. Happy early Thanksgiving!!