Lochinvar mod/con boiler question

keyote

regarding the sizing I dug way deep into this with Gordys help and modcons are actually most efficient when modulated down to about 50% in other words unlike other boilers a modcon is better oversized and then run at low modulation. of course there a point of ridiculousness but from all the studies gordy posted Id rather be a bit oversized for design day and running at low modulation most of the year

kalex1114

@Leon82

Where is the setting for this? - I would bring the 81 degree up to about 110 minimum.

njtommy

I believe his talking the minimum supply water temp setting. You would set 110 swt to say 60f out side or 55f out side for your odr curve.

keyote

Im having a similar issue with my KHN 085, in brooklyn ny, radiant floor system though. can any of you guys suggest a starting point for a curve for me? My loopcad was way wrong about its swt prediction for that top floor maybe bvecause i didnt use warm board so ill likely need to be hotter

kalex1114

njtommy said:

I believe his talking the minimum supply water temp setting. You would set 110 swt to say 60f out side or 55f out side for your odr curve.

Ah got it. So instead of 68f, 82f set it to 60 at 110

Leon82

> @kalex1114 said:
> I believe his talking the minimum supply water temp setting. You would set 110 swt to say 60f out side or 55f out side for your odr curve.
>
> Ah got it. So instead of 68f, 82f set it to 60 at 110

Yes. The heat seemed more stable above 110 for me

kalex1114

Hello All. I didn't forget. Spent time dealing with Hvac company about this.
I ended up getting a call from the service department and they sent out their main lochinvar person to assess the situation. After on site visit and troubleshooting he determined that start up was incorrectly done and too many changes were made to the gas valve. He contacted Lochinvar and today gas valve was replaced. That solved the issues with different sounds that my boiler was making. At first it was rumbling sound. Then it started to foghorn and pop. After replacement, no more sounds and overall performance is quieter. Only sound that it makes now that I notice is when its in standby. There is a slight vibration sound that goes away if i press on the front and top covers. I emailed lochinvar about it.

Also with the gas valve lochinvar representative arrived and took a look at all the settings. So the issues i've been having seemed to be related to initial startup programming that was done incorrectly. Lochinvar rep pinpointed the issues were related to Cascade settings. He said that issue was that Cascade address was set to 0 and function was set to L/L (Lead / Lag) which caused the behavior of not modulating and overshooting the temps. He changed it to address 1 and Alternative Leader was set to N.

After that boiler was behaving correctly with system/outlet controlling the temps. I also set the pump speed to Hi from Medium on the boiler pump.

I want to thank everyone who assisted me, Especially Boon who graciously offered to help offline and spent a good amount of time assisting me.

I adjusted the curve based on the combination settings that Leon82 and NJTommy provided. We will see how it goes once it gets colder but for now it seems to be working.

I was also able to reduce blocking and cycling on DHW side by using 187F /3f offset and adjusting the DHW pump speed to 3 from 2. With this setting boiler starts to modulate down as it approaches temp. i did see one blocking today but not sure why. Going to keep an eye on it and try to see if i can adjust this even more to eliminate it completely.
I will update my post as the winter goes on but now everything seems to be in much better shape then before.

I also noticed one big benefit of using ODR and this boiler is that with lower temps going to my baseboards heat distribution is much more even and comfort level is much better then before.

Thank you


Alex

Leon82

In the anti cycling parameters you can set up to a 10 min delay before restarts on heat calls.

When you have this set it says blocked anti cycling for 10 min after a heat call or set point has been met.

Outside temp can also block a heat call

keyote

Thanks for update Alex. if you can add anymore Id appreciate it, particularly about this over adjusted valve issue. Boon mentioned that and now Im thinking he heard it from you.
Thing is Im having exact same noises like a washing machine pumping out, often on startup or soon afterwards when it needs to mod down low.The thing is I have never touched the valve adjustment, the analysis was within the spec range so i left it. I have heard though alaska tim finds it should be about 9.2
Thing is everyone I know of with this boiler which I really want to love has this problem, and Im wondering if maybe their valve is a lemon, I am pretty sure I heard somewhere they once remodeled it already. Well any more details will help me figure out whats going on with mine. My guess is their manuals spec range is way too wide, and they factory ship them at the very low end of spec, and since unlike boons mine worked ok for a while, getting worse over the year, Im guessing it now needs to be broken down and serviced and then have the mix reset.


also if any pros can comment on this idea that the gas valve can only be tweaked once. The manual says you can turn it 1/8 turns as many as four times, but verbally they seem to be adding that you can never turn it in the opposite direction once turned in one direction and cant reset it again once set one time. Does this seem to be normal for a gas valve.

Leon82

I don't think it's normal. You should be able to bottom it out and come back a set amount of turns to get a baseline to begin an analysis.

The video posted in boons thread says after 4 adjustment to look at all the other installation issues again. I take that as there needs to be something way out of wack with an install. A call to the tech branch is probably in order and they will most likely not give adjustment advice unless they are licensed.

keyote

Thanks Leon, which what post has that video? yes the manual say that if after four 1/8 turns you still dont have problem solved go back to double check other possibilities. if i recall the two they mention are your flue temp and return water temp should be withing 54 degrees of each other mine are within a degree, the other was the milliamps an the flame being minimum of i think 9.5 at 100% mod mines been 10.6- 11 at mid range mod. I thought I had air in my water for a week i spent chasing that and they never mentioned what it most likely was. Im not a licened plumber but I am a 35 year HVAC foreman but airside. Im not averse to paying someone but i hear prices like $600 to just set the mix and wonder what it will cost to tear it apart and clean the burner and HX as well and why is a 4000k boiler needing this much work when its factory setting havnt been touched and why i know three other guys with the same issues.

Leon82

> @keyote said:
> Thanks Leon, which what post has that video? yes the manual say that if after four 1/8 turns you still dont have problem solved go back to double check other possibilities. if i recall the two they mention are your flue temp and return water temp should be withing 54 degrees of each other mine are within a degree, the other was the milliamps an the flame being minimum of i think 9.5 at 100% mod mines been 10.6- 11 at mid range mod. I thought I had air in my water for a week i spent chasing that and they never mentioned what it most likely was. Im not a licened plumber but I am a 35 year HVAC foreman but airside. Im not averse to paying someone but i hear prices like $600 to just set the mix and wonder what it will cost to tear it apart and clean the burner and HX as well and why is a 4000k boiler needing this much work when its factory setting havnt been touched and why i know three other guys with the same issues.

It was the Lochinvar u video in his post about training. But it basically says what you did about the 4 turns

Boon

It was my understanding that a batch of boilers with serial numbers 15xx and maybe some of 16xx left the factory that weren’t properly adjusted or were not adjusted at all. My boiler, Keyote’s and Alex’s are all in that batch.

I recall my valve needing some unholy adjustments to get it from 8% (wouldn’t ignite) up to 9.1% (almost perfect). After some classes/training I’ll try to take it a little higher. For now, it’s good enough.

keyote

Yeah the reason I asked is the lochinvar u videos are broken as usual, they will only load audio with no controls, people have been leaving complaints in the comments for months but nothing's been done. they are broken in some way every time i go to use them **** have they no youtube in tennessee? Sorry for rant Im losing patience with lochinvar my conxus was a huge fiasco as well

kalex1114

@keyote Here are the videos I took:
Original video. This was a rumble sound.
https://youtu.be/2oGpTLJ4sMs?t=19

I called hvac company over and they sent a first guy. we called lochinvar and first thing they made him do was to open it up and make sure there is no debris inside. That was done. After that we called and next thing they said was to do combustion analysis. initial settings was at about 7.5%. Lochinvar support suggested we aim for 9.5% at 100% fire. Hvac service tech got it to 9.5-9.6% . They also said to do low fire analysis but guy didn't know how to do it. I kept telling him about service mode with paperclip and he didn't want to listen. after that 2 new noises showed up. At low fire there was a foghorn noise but it wasn't very loud. https://www.youtube.com/watch?v=D9TrergasEQ and another noise that was a **** to capture. It was a very loud pop which my dog didn't like It was as if something was blowing up inside the chamber like a mini explosion. But no damage was present anywhere in the boiler room. That happened at least once a day. When lochinvar specialist from hvac company showed up I explained what the other guy did where he turned the adjustment a lot of times and didn't do service menu. This guy was much better equipped to deal with the issue. He adjusted the adjustment screw as well as the other screw that said not to touch. I forgot whats it was called. Then he offered to exchange the gas valve. His explanation was "i want to make sure its done right and don't want to come back". new gas valve was perfect out of the box with no adjustments needed. Speaking as non professional but dealing a lot with tech support in server and datacenter field I kind of got the vibe that there were issues with gas valves but they didn't want to admit it. If you want i can take the cover off tomorrow and take a picture of the new one.

Now I have last noise that I want to deal with but this one is when its in standby

This is the noise i hear now https://www.youtube.com/watch?v=0Dl50vUinAU Its a lot louder in the video as i put the phone right on top of the boiler to record it.

keyote

Thanks for info Boon. can you quantify ''unholy adjustments'' in 1/8 turns. im thinking Ill adjust mine after cleaning it gaskets etc coming tomorrow, and no one returned calls so i think Ill dive in, wish me luck.

kalex1114

@keyote try using IE browser. i found that thats the only one worked for me. I tried it on safari, firefox, chrome, edge and they were all broken. IE worked. IE 11 running on windows 10 laptop did the trick. My boiler is also 1549 serial number 154910228
1549 is first week of december 2015 production run. If you can, I would push for replacement. With new gas valve I noticed that boiler sounded differently then with original valve. Could be placebo effect but I don't think it is

kalex1114

@keyote there is a video on lochinvar U on how to clean it. It doesn't look too hard. I saw the guy open the HX and it wasn't too complicated. Just bunch of screws to keep track of

keyote

Alex Thank you so much that was very helpful though confirming i think my fears. My noise is more like your first video just not as sharp and usually more even once Boom hipped me to it likely being combustion not water issue and i watched the flame while inducing it to start and make noise i watched it dance to the noise and the pop i think is what happens at the end, it seems to almost die out but the gas seems to keep coming but not catching, i dont know all i know is it ends with a little orange fireball and a pop then out. Mine came set at 8.5 and since it was withing manuals range i left it. yes it definitely sounds like the valves are garbage, now im going to have to tear it apart twice because i have to get it working for tenants tomorrow then ill demand a new valve.%^$#@^&*

keyote

Oh great tip, i too tried firefox and chrome and brave. i gave up befor IE hope that works I have the gaskets and other parts just wish i had a new valve - BTW i noticed the bottom of cabinets been getting some water recently today I finally found its the internal factory brass union coupling into the HX from the supply niple is dripping.

Leon82

That kinda sounds like a transformer buzz

kalex1114

It’s possible. I know that if I press the front panel in sound becomes quieter
@keyote try bringing it to 9.5% they should get rid of the noise . I checked mine it’s dry on the bottom

keyote

Thanks Kalex yes i noted you said they are now recommending 9.5, that keeps going up. but I assume they have accrued the most data. if these new valves are preset correctly I think I should insist on one.
But first Im convinced the machine has now to be cleaned, burner and HX because the problem got worse over the year until it now locks out a lot and cant mod a steady blue low flame, i think its increasingly fouled itself.
What really disturbs me is both you and Boon despite reporting marked improvement neither of you report 100% improvement. And my experience was although i started with much better almost perfect but not quite, it seemed over one year of light duty it slowly degraded to failure. this makes me think anything less than perfection and this boiler is working its way back to a complete fail within a year.
The manual implies it needs to be taken apart every year this seems absurd at the prices guys want to do that, to say little of the difficulty of finding qualified people for this complex machine. i wonder if this is routine for mod cons.

kalex1114

I only had it replaced just today so don’t have enough data but I will let you know how it goes through the season. I can say that it’s definitely better with new valve in place. What is interesting is that I had the boiler in place since June and dhw cycles never had these sounds. It only started when I turned the heat on.

keyote

mine is the same, DHW calls are 100% mod, it only has trouble when its got to mod down on heat calls, Im radiant so my heat calls are low mod this time of year. And it seems you and Boon are having minor issues at low mod and warm weather. Can I ask what they charged and what they did for it. Yes please do keep us informed.

kalex1114

No charge in my case. It’s a new install so I get 1 or 2 year full warranty including labor. One year for sure but I think they included 2 years in my install. After that hopefully not a lot

kalex1114

@Leon82 you are right. its the transformer buzzing. its the transformer that is located in front where the low voltage panel attaches. When the bottom of the panel is attached i hear the buzzing louder. Tried to put few weather sealing strips around the front, it helped but not by much. Any suggestions on how to make it less apparent?

kalex1114

And I'm back mini explosion sound is back. This time I had my ipad running conxus software and my iphone recording on top of the boiler. So what I was able to figure out is that it started DHW cycle at 100% then modulated down to 58%. Went into anti-cycling /blocking for 1 minute then I saw pre-purge on the ipad and then I saw ignition and the bang. Here is a trimmed audio of full cycle. Bang can be heard at 6:41 mark https://www.dropbox.com/s/6s45jbqz8ybn3uc/trimmed-bang.m4a?dl=0
it sounds a lot louder without iphone noise reduction

Leon82

Try and look inside the sight glass while it's sparking to see when the ignition actually occurs. If you turn the lights off you can see better.

See if it fires on the first Spark attempt or it takes two or three

NY_Rob

Can you actually hear the inducer motor spool up to speed for the pre-purge? Is it running for the same length of time it always runs for?

Maybe go outside and check your intake screen for foreign object blockage?

Leon82

> @kalex1114 said:
> @Leon82 you are right. its the transformer buzzing. its the transformer that is located in front where the low voltage panel attaches. When the bottom of the panel is attached i hear the buzzing louder. Tried to put few weather sealing strips around the front, it helped but not by much. Any suggestions on how to make it less apparent?

I don't know the Transformer on my boiler is quiet. My taco box Hummed for about a year and now that's quiet too so who knows

keyote

Using iphone to watch flame works in video mode it gets sound too.you def have different sounds than me. See if yours correlate with flame, Flame should be blue but sort of transparent and clearly defined and even. when my sound is going the flame is none of those things and usually ends with almost dying then flaring up into an orange ball of fire then it goes out. All my parts cam so Im going to clean the burner heat exchangers and check for debri from intake to flue.
I had a long conversation with tech support, got a better person who at least didnt imply it was somehow my fault. They insist they have never had to redesign the valve but that sometime valves can theoretically go bad.Apart from that it was pretty much what the book says, interestingly it turns out the book revision they are on is now J and them one i got with my unit one year ago was A, And at least one of the things thats been revised is the CO2 range now starts at 9.o
said i should shut my boiler down if its got little fireballs going on- DUH,basically they want me to pay to have it cleaned, then pay more to have combustion analysis re done according to their revised manual, then if it the valve well its not under warranty after a year since i have a tenant, and if it happens again by next year oh well what do you expect for a $4000 boiler?
well Ill clean it up tomorrow and guess il will have to pay for another analysis, but if it gives me the slightest trouble after that well its too bad it might have been a good product if they had put more effort into it.

kalex1114

Intake and vent are both clear. It doesn't happen all the time. I haven't watched the actual flame yet

It seems that applying weatherstripping helped. its now quiter

Leon82

How long are your vents?

kalex1114

not long. picture attached and they terminate right on the outside of the blocks with flush termination kit.



This is the picture:

keyote

isnt PVC bad for HX

Zman

I would see if it is possible to get a manufactures rep to give it a look. You and the installer have done your diligence, it would be a good time or them to step up.
I know in Colorado you can get a knowledgeable Lochinvar rep with a combustion analyzer to come out when you have a problem child like this.
Some times making noise about lemon laws and refunds will accelerate the process.

Leon82

> @keyote said:
> isnt PVC bad for HX

They do want 7 feet of cpvc initially if I recall correctly

kalex1114

Lochinvar rep was here for valve replacement. Although i didn't see them using the combustion analyzer at the time of the swap. He was the one that found cascade setting. I didn't get to the point of making noises yet. But its creeping up

keyote

You would think if they replaced a gas valve because of troublesome combustion they would certainly put the analyzer of the flue and a manometer on the gas and venturi, You might ask what their readings were see what they say. But what do i know Im just a tinknocker