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Indirect loop off Combination Laars Endurance?

narcaparbebranarcaparbebra Member Posts: 32
You could always use the EDP 110 (just the boiler without the tank)and add a 50+ gallon indirect.


  • OcelarisOcelaris Member Posts: 22
    Combination Boiler with Indirect Loop

    We're looking at replacing our 50 year old natural draft federal boiler. Our budget permits only a mid efficiency boiler like the sealed laars. Our contractor likes the Laars endurance, and I'm apt to go with that. But it's a 2 family home, 3 bathrooms, 1 Jacuzzi tub ~100 gallons, a washing machine, maybe a dishwasher down the road. So the 20 gallon tank in the combi EBP 110 unit isn't going to be able to fill the Jacuzzi tub. So I asked if he could put an indirect off of that boiler so we have plenty down the road. He said he would, but I don't know if we're making trouble for ourselves with a unique install, and lowering our efficiency. I realize that we won't have a priority over ride or anything like a normal indirect tank with a flow meter, but are we going to see a significant increase in gas useage because of this secondary storage tank? Now that I think about it, I don't know if it's an indirect loop or a storage tank off of the 20 gallon already built into the unit... but I would assume a storage tank if it's using a mixing valve.

    Just looking for a "yeah that's not crazy" type of feedback, because our guy will do it (and I found him through this site), but I don't know if we're being outrageous consumers and we shouldn't worry about the relatively paltry supply of 4gpm filling our tub. We honestly never use the tub, so if we could run 2 high useage showers at the same time comfortably, I wouldn't even bother with the secondary storage tank, but this isn't I assume the normal 1 bathroom condo that this boiler is spec'd out for. On the other hand if the secondary tank is going to be a huge energy drain, I wouldn't want to waste that...

    TIA Bill
  • OcelarisOcelaris Member Posts: 22

    I don't think the EDP model has a priority domestic hot water call, just a hydronic boiler. So would have to add all that extra stuff to get it to do what we want. I'm not so sure this EBP is meant for our purpose, or that 4gpm can satisfy a house which his the 50-100mbh rating... It's kind of a funky product what you think about it, what kind of building needs that large amount of BTU but only that small amount of domestic hot water?
  • W MartinW Martin Member Posts: 1
    Laars Endurance

    I have a Laars Endurance Combination gas fired boiler and have had a lot of problems with the boiler locking out.No one seems to have an answer for this problem. I would not recommend this boiler.
    On demand Indirect domestic hot water will not supply enough hot water you will have to install a storage tank
  • JoannieJoannie Member Posts: 115

    Some clarification here.

    The 20 gallon tank in the EBP is NOT domestic water. That is boiler water. The domestic is made through a plate heat exchanger, and the Endurance does not store any domestic water. That's a commonly misunderstood part of the Endurance. The 110 unit is good for 4 gallons per minute. The 175 is good for 5 gallons per minute.

    In installations that will have more domestic water draw than this, a direct storage tank can be added, to store the domestic water, or the EDP can be used with an indirect water heater. (EDP is the heating only version of the Endurance.) It is most common to add straight storage, and you keep the benefit of the 20 gallon buffer, which is nice if you have mulitple heating loops, and/or small loops that don't need many BTU's.

    Personally, I'd be uncomfortable using any unit that supplied 4 gallons per minute for a 2 family dwelling. I'd be looking for some storage at the point, but your installer is closest to the job, and is the the best one to determine if it will work for you.

    I hope this helps.


    Laars Heating Systems Company
  • JoannieJoannie Member Posts: 115

    Has your heating contractor contacted Laars about this? If not, please have him call us at 800-900-9276 and get connected to a service tech. We also have service managers in the different regions of the country that can help.


    Laars Heating Systems Company
  • OcelarisOcelaris Member Posts: 22

    Thanks for the reply Joannie. I posted here specifically becasue I know Laars visited these forums. And glad to hear the clarification.

    I am not worried about various non-professional poor opinions. I mark those up to poor installation by a bad installer. You sometimes have to cut through the here-say when speaking with non-professionals. No offense to any one's personal experience (including myself as I am a consumer). As a tech in another field, I have to see it personally to believe it. Since I will never see your problem, I can only believe what the most well informed people are saying. My experience has shown this to work the best when choosing a product; and hence why the Laars is still on the top of my list.

    My contractor DID recommend this additional storage tank on the EBP, I just didn't know if this was a normal thing. He likes the Laars, and it's relative efficiency is what we're after; it's amazing there aren't many more products in that middle price/efficiency range.

    What is the purpose of that 20gallon boiler storage if we're not using the boiler half the year? Wouldn't that just be a waste of money? In fact I can't think of any place which needs heat all year round... We have a 2 zone system, so only 2 loops.

    Thanks for the help, Bill
  • narcaparbebranarcaparbebra Member Posts: 32
    Laars Endurance Lockout

    Is the intake air mixing with the exhaust? Does the unit try to light three times and then fails? What is it doing before the lockout happens?

    I have several of these boilers in tenant apartments and have experienced similar issues but they have been fixed and all of them work fine now.

    Venting is critical. The concentric venting must be sloped away from the boiler so any condensation drips out of the vent and not into the boilers ignition rod.
  • JoannieJoannie Member Posts: 115

    Hi, Bill.

    We still visit and respond, and try to help people that want help.

    The 20 gallon buffer tank is there for the domestic water. The unit keeps the 20 gallons hot (well insulated and very little heat loss) so it's always ready to heat the domestic water. And if there is just a short call for domestic (someone just washing their hands, for instance), the boiler will likely not even have to fire to get hot water to that fixture for that long.

    The 20 gallon tank is only in the EBP (combination) model. It's not in the EDP (boiler only) model, because we don't need to react to the domestic water like that.

    It can benefit the space heating side, though, in cases where there are multiple small zones, etc.

    I hope this helps.
  • gerrygerry Member Posts: 33
    May not need priority dhw

    especially if the two heat zones are high temp supply.
    I'm not certain but the EBP may have priority biult in sensing the dhw outlet temp drops below a certain temp the system pump would shut off like the Heat Makers did it.
    Also do put a mixing valve on the hot water supply.

  • JoannieJoannie Member Posts: 115

    Hi there.

    It's done differently than the Heatmakers were.

    The Endurance has a domestic water flow switch that switches an internal valve in the unit to move it from heating mode to domestic mode. (So, if you are using a storage tank in conjunction with the Endurance, you have to make sure you don't put the pump between the tank and the boiler on constant circulation, or there will always be a call for domestic, triggered by that flow switch.)

    There is also a sensor in the boiler tank that will charge the tank when that temperature drops.

    Hope this helps to clarify.
  • McKernMcKern Member Posts: 43
    Laars Endurance

    My Laars Endurance locked out again today the last time was October 29. I had a service man look at it October 22 His suggestion was to replace the boiler as they are trouble.I have had this boiler since 2004 and it will lock out 2-3 times in one day and then be fine for weeks, months. If anyone has the solution please respond
  • JohnLJohnL Member Posts: 38

    From my experience typical Lock outs are due to exhaust mixing with the intake air or condesation from the exhaust drips onto the ignitor. The unit will try three times for ignition and then lock out.

    Make sure the exhaust pitches away from the unit or has a drip T if it slopes towards the boiler.

    Have you inspected the exhaust and ignitors.
  • Bob ForandBob Forand Member Posts: 305

    With all due respect, and not trying to pick a fight, but I had to call in to the Tech line a couple of times over the last few weeks and the wait time is almost unbearable. On one of the calls I was fifth in line and waited 53 minutes on my cell phone to get help. That hour is time I will never get back or an hour lost to get to the next call.

    Is there any plans on adding assistance to the tech dept for these "time of year" calls ? I spoke with Noel and I believe Dave. They were personal and knowledgeable, which is a huge plus. It was a good experience except the down time waiting in line. Either you are understaffed or your products must have a lot of issues.
  • McKernMcKern Member Posts: 43

  • JenJen Member Posts: 2
    Endurance keeps running

    I did have a LO problem and a Laars "expert" told me the flame sensor was bad and it was replaced.It never locks out now. Now my boiler will not shut off. I will run constantly without a call for heat or hot water. I have to manually turn it off to prevent an enormaous fuel bill. Can anyone help ?
  • mike glassmike glass Member Posts: 53

    Ron, Try disconnecting your TT connections to see if you have a wiring problem or bad control. With no call for heat, the boiler should stop running.
  • McKernMcKern Member Posts: 43
    Laars Endurance

    The boiler LO again tonight. There was no call for heat or hot water I restarted the boiler and the temperature was 172 f and the boiler did not fire. On a call for heat the boiler started up and worked fine and returned to ON at end of call for heat.This seems to me to be a control board problem Has Laars fixed this control board or issued a new one.
  • saussyHensaussyHen Member Posts: 19

    I do have the LO problem. I was told to replace to flame sensor which didn't fix the problem. If the unit stay on LO for a long time, after reset, the EBP-110 would explode (Safety corcern). My tech told me it could be because too much gas is built up inside. I had already replaced the board for a different problem. The EBP-110 has a blue side. LO problem started at the begining of this yr and has worsten.
  • saussyHensaussyHen Member Posts: 19
    Laars Lock Out

    Well, I am another lock out victom of Laars system. It has run for 3 years without a problem, now it has started locking out intermitently about two months ago. The service people I had install the system have given up trying to figure out what is causing this.
    I am getting ready to call the gas company and replace the unit. What is Laars doing to help solve this?
  • mike glassmike glass Member Posts: 53

    Has the combustion been set up properly? Is the Unit LP ofr natural gas? Does it have an air shutter adjustment? Sounds like improper combustion a possibility.
  • JeffJeff Member Posts: 2
    Laars EBP175 domestic hot water problems.

    Help!! Any suggestion would be most welcome. Off late the domestic hot water on my laars EBP175 is acting up. We used to be able to get sustained hot water without any problems (4years since we got the system. This is the one that looks white with blue trim).
    Starting a week ago, we get cold water for almost 30seconds before hot water comes back again. We start off getting hot water normally, and then the temperature goes down slowly and then to cold water. And then the temperature goes back up but never as hot as we used to get.
    We have not touched anything related to the boiler (including the mixing of hot/cold water). Does anybody have an idea what may be wrong. It is pretty annoying when you are having a shower to get very cold water out of the blue.!.

    I have noticed that when we ask for hot water, the boiler after a while, seems to be short cycling. In the sense the temperature seems to rise from 172 to ~192 and the boiler cuts off and then starts trying to do that again after a brief cooling period (may be 30s). Sometimes it does get over the 192 degrees threshold, and it stops doing the cycling and goes through a full boiler cycle.

    Not sure if that is relevant. Any help is much appreciated.
  • TimSTimS Member Posts: 82
    Possibly a cross connection?

    First verify you have hot water coming from the laars to the mixing valve, I'm guessing you do since the boiler is 170* plus .You say it started a week ago, has any other plumbing or remodeling been done about same time like tub/shower valves , hot recircs , I am susspecting you may have a cross connection (cold water moving into hot water line) . Does this make sense?

    A simple test : shut off the cold water supply to the mixing valve and the laars now open a hot faucet you should not get much water , if water runs cold and steady then you have a cross connection some where!
  • JeffJeff Member Posts: 2

    Thanks Gerry for the suggestion. I did have my bathroom re-modeled over the summer (6 mo aqo) with one of those fancy mixing valves for the shower, where you didn't have to adjust for hot water every time. But at the point when the project was complete, we were getting continuous hot water. Maybe the supply water was warmer in the summer, but we were not getting raw cold water out.
    I will try your experiment of shutting off cold to the LAARS and see that if we still get cold water out of the hot water spout in the sink.
    Thanks for your help, and happy holidays. Your help is much appreciated.
  • JenJen Member Posts: 2
    luke warm water

    can't get hot water anywhere in the house. just luke warm. tried replacing the mixing valve, didn't help. maybe it's because cold water is soooo cold? how do i up the temp in the tank? i have the laars ebp 100.
  • FrankFrank Member Posts: 40
    another LO issue

    I have a EBP 110 which randmly locks out. My issue is the F-2 or over temp switch. what are some of the causes of an occaisional over temp Lock Out?
  • W MartinW Martin Member Posts: 2
    Larrs EBP LO

    Over temp f 2 Error code will not cause LO All boilers are tested at the factory and come with errar code in memory (Read manual can be obtained on line at Larrs web site) I had LO problems and replaced PCB Jan. 09 and have had no more LO s It is a very easy 10 min. job to replace PCB Larrs will want you to get a service tech and preform a dianostc exercise when they should know the problem is with their PCB as the wholesaler told me that it is a popular item The PCB I installed was series 7 and after replacement the preformance of boiler improved as well as not Locking Out
  • narcaparbebranarcaparbebra Member Posts: 32
    Laars endurance EBP F-2 problem

    how do you reset the f-2 error, tried everything but still f-2
  • W MartinW Martin Member Posts: 2
    Error code

    Error code can not be erased It stays in memory and is replaced by most recent manual can be obtained on line at larrs
  • George PeteyaGeorge Peteya Member Posts: 9
    Endurance Manuals


    If you have a new style Endurance (gray jacket with yellow around the digital display), you can download the manual at Go to "Document Downloads," then "Product Manuals."

    If you have the old style Endurance (blue sides, crean/tan front), please call me at 1-800-900-9276, Ext. 513. I'll email you the manual - it's not on our website.

    George Peteya
    Tech Service
    Laars Heating Systems Co.
  • rogGoarfsoonyrogGoarfsoony Member Posts: 8
    lo or too much...we cant win??

    so my system is in LO, again. It goes to LO overnight and we start every morning pushing the reset button. BUT TODAY, reset is not working, nothing. So I turned the unit off, and back on again, still goes to LO. This has been happening for years, we just adapted to hitting the reset before you take a shower!!

    If it's not in LO, it goes to the other extreme of continuous pumping of heat into the house, regardless of what the thermostats are set at. We have to turn the valves off to stop the heat and then open them up when we want heat.

    Nice system.....Don't buy one!!!!
  • JoannieJoannie Member Posts: 115

    This has been happening for years? Have you called a heating professional in to diagnose the problem? Has your heating professional called Laars about this?

    The contractor should call 800-900-9276 and press 4 and then 1 to talk to a tech service person here. It is often helpful to have him call from your boiler.
  • ummiummi Member Posts: 1
    Laars Endurance 3 years old no hot water

    Ive never had a hot water issue with this until this am. The temperature read on the front of the unit will not go above 76. When it gets to 76.8 I get an OFF error code. I'll reset it then it will struggle to get above 76 again and back to the OFF code. Please help
  • SlimpickinsSlimpickins Member Posts: 314
    could be a lot of things

    Have you had the unit serviced since it has been installed? There are so many things it could be, flow switch, anti condensing valve, sensors, controller, combustion problems. This isn't your Grandpa's boiler or something you are a neighbor can fix. You need to call who ever installed it or a qualified Laars service guy. I know, bummer its a holiday weekend.
  • sandragirlsandragirl Member Posts: 1
    Ref: Laar Heating EBP

    I need help, my endurance is flashing a F5, no heat downstairs in my home. I have heat upstairs, two separate thermostats.  need to know what F5 means, help this has been an ongoing problem since October 2011,  bought a new one for upstairs and heating if fine but downstairs is freezing. 
  • IronmanIronman Member Posts: 3,409
    F-5 Code

    The F-5 code is a tank sensor error, meaning the tank sensor or its wiring is faulty. See the attached manual.

    You will get more responses if you post this as its own separate thread instead of inserting your question in the middle of an old thread.
    Bob Boan

    You can choose to do what you want, but you cannot choose the consequences.
  • SpencSpenc Member Posts: 1
    Endurance boiler

    I have a endurance boiler I'm working on and it's got no hot water, I put a new flow switch in back in July because they had no hot water, now they called with no heat. I've changed the anticondisating valve,control board and it's still not working
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