System 2000 EK1 Sanity Check... new homeowner

NEMatt

Hi everyone. My wife and I just purchased our first home in NJ which is heated by a Sys 2000 EK1 (2009 install). We are actually like 30 minutes from Energy Kinetics themselves.

I have done some reading on the system theory of operation and have observed a few full domestic hw heating calls. Could be my imagination but I think there might be some weirdness going on.

When the tank aquastat starts a hw call, the correct light comes on, circulator light illuminates, burner starts. Once the bar lights on the manager get to a certain level the light on the right hand side illuminates indicating the hw call is being answered. All seems correct up till now.

However both the output and input temps (dial and bar gauge) on the boiler side seem to rise pretty rapidly and eventually hit what I imagine is the high temp cutoff prior to the hw call being satisfied. Burner turns off for a few minutes, circulator stays on, and both the call and answer hw call lights stay on. At this point the domestic hw line out of the PHE is pretty damn hot. Hard to hold my hand on. While the line into the PHE is rather tepid.

The boiler will go through this a few more times before finally having the tank aquastat say everything is up to temp and turning the call light off.

Is this indicative of the PHE being blocked up on the domestic side? Something else perhaps?

rick in Alaska

Sounds like either the plate exchanger is plugged, or your circulation pump isn't working. If you turn on a call for heat, and the light on the right comes on, does the pipe going to the zone start getting hot? If it does, check it a few feet from the boiler and see if it is hot there. If it does not get hot there, then the pump is probably out.
P.S. if the pressure in the boiler is at zero, it can give the same symptoms, so check the pressure.
Rick

NEMatt

If I wanted to backflush the PHE to see how it was flowing and if there was any crap it in, do I simply close the ball valve directly below the circulator and open the outlet between the circulator and PHE and catch the water for a few gallons?

If the domestic circulator wasn't working would I be getting hot water at all?

rick in Alaska

I would need to see a picture of the piping around the heat exchanger to know that. But, that sounds right.
If the heating elements are above the boiler, you can get gravity flow up into them that would make them heat up. You would not be able to heat the house very well if it was cold out, but since it is summer time, it probably is just enough. That being said, i amend my previous post to have you see that if the outlet heating pipe does get hot, that it should get very hot almost immediately after the zone valve opens up, but If it is gravity flowing, it will heat up slowly.
Rick

NEMatt

Piping layout on the dhw side below. There is a ball valve hidden from view just below the circulator.

rick in Alaska

That portion you are showing is on the domestic water side, and yes, if you close the valve below the pump, you can flush the heat exchanger, but it will only flush the domestic side. If the heat exchanger is blocked, it would be on the boiler side. That is the piping we need to see.
Rick

NEMatt

Ohh, I figured the blockage would definitely be on the dwh since the output to the tank gets darn hot and the input after the circ stays tepid. Boiler side in and out are both very hot as if it isnt transfering much heat to the dhw side.

rick in Alaska

I guess I read it wrong. Really read it wrong. Not enough coffee yet I guess.
So , yes, try and see if you get good flow out of the drain valve with the ball valve below the pump off.
Rick

NEMatt

Haha that'll happen.

I'll give it a go and see what comes out of the HE.

Roger

Thank you for your question, @NEMatt , and for everyone’s comments.
In the simplest terms, if the hot water tank calls and the burner light on the right hand side turns off quickly during the call, then flow through the boiler is good and there may be a flow issue on the domestic side of the plate heat exchanger. If the burner light stays on and the burner turns off because of the high limit, then there is likely a flow problem on the boiler side. Hot water may still be produced with a domestic flow problem, but it will takes longer.

Here is a link to a diagnostic guide for hot water:
https://energykinetics.com/wp-content/uploads/2015/11/D-7-9_Tech_Hot_Water.pdf

Best,
Roger

NEMatt

Roger,

Thanks for the reply. I'll take my IR temp gun down to the basement and have a look at the piping. I do think the burner is essentially cycling on the return limit aquastat so there is probably some flow restriction in the dhw side.

Is that an excerpt from a tech manual available to the public or is that an internal document?

Roger

I believe anyone should be able to access that document through the link provided.

NEMatt

It seems like only those three pages, not the full document. I figure there is other helpful tech info in the other sections.

Roger

Thank you, @NEMatt , I just posted the section relevant to this topic. The entire manual is not accessible.

NEMatt

Finally got around to backflushing the PHE. It coughed out some schumtz but flowed perfectly thereafter. Filled like 3 gal into a Home Depot bucket and called it good.

I watched a short heating call afterward and it seems like it is acting more normal. PHE inlet water is still climbing right up there but the outlet is not pegging up high, so it is actually rejecting heat to the HWH through the heat exchanger again. I'll watch a longer HWH call later today but definitely the correct path.

The stuff that came out was best described as like greenish coarse salt. I assume green because of copper corrosion (low pH and previous owner did not have an acid neutralizer installed), but I am not sure about the mineral nature. Wondering if flushing whatever is in the HWH itself would be wise at some point soon.

Jamie Hall

The green cation is probably copper. Which used to be in the pipes, but... the anion is probably carbonate.

Flushing is almost never a bad idea -- but like anything else, enough is enough sometimes...

Roger

I'm glad to hear you've improved the flow through the PHE, @NEMatt . In general, the materials backflushed out of the PHE arrived there because they were entrained in the water. Sometimes the source can be a water treatment system. You can always flush your cold and hot water systems; if you see any concerning amount of materials, you may wish to consider whole house filtration or treatment depending on what you find. Keep in mind that it may have built up in your water heater over 11 years (since 2009).

Alternately, in hard water applications, minerals like lime can plate out and build up (these minerals are inversely soluble so they become less soluble and precipitate out when heated in water as opposed to sugar and salt which become more soluble in water when heated). If hard water is an issue, the heat exchanger can be cleaned like a tankless coil and we recommend adding a scale stopper or similar if a treatment system is not used or maintained.

Best,
Roger

ratio

Try here.

hot_rod

Positive or negative ions.
https://www.caleffi.com/sites/default/files/coll_attach_file/idronics_18_na.pdf

fenkel

the heater ex-changer for your water heaters needs to be cleaned periodically to prevent this from happening. Most systems will have drain values that you use to run a cleaner thru the ex-changer. we general use vinegar for cleaning these items... we use a pump in a pail for this processes...
H-D, has them for under a couple hundred bucks.. I think they call it a flush kit for tank-less water heater..
we generally will run the vinegar for an hour.. then rinse with water and return to normal operation.. sometimes you'll need to engage the ex-changer's pump to help with the processes... or to open a 3-way valve.
Some manuals will have this process outlined in it... otherwise check the internet for videos.. you tube may help...

Grallert

You might be able to isolate that exchanger from the system and remove it. I cant really tell. If you can than take it off and fill it with white vinegar. let it sit for a while run clean water through it and reinstall. It's worked for me a few times with those.

NEMatt

Backflushing seems to have worked just fine for now.

stonebutson

Back flushing plate exchange still part of annual maintenance? Chuck it and start fresh?