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Bosch Greenstar 151 Condensing Boiler not maintaining set temperature
ant930
Member Posts: 111
in Gas Heating
This system was installed in May 2014 and since the weather has turned extremely cold, my downstairs zone will not maintain the temperature set on livingroom thermostat... upstairs is fine.. it it does finally reach the set temp which is generally set to 70 degrees, ... during this frigid weather... temp falls during the night and upon waking will be at times, well below 70. sometimes as low as 63 degrees!... BRRRR! Installers telling me that its the house which is 25 years old... saying poor insulation,,, windows,,, placement of baseboards... etc...I never had issues before when I had an oil system and it is my belief that it is none of thos things and should maintain the heat even if it has to run all day.. they claim the settings are correct... In doing some research... I discovered that the outdoor reset sensor is placed in the wrong area...from what I have read in the manual... it should not be on the south side of the house or near anything that sould influence the temp such as the boiler exhaust pipe... would the placement of the outdoor reset possibly affect the issue I am having?
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Comments
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Quite possible that the ODR sensor is picking up some solar? That would make it think that it's warmer than it really is, and set the circulating water temperature down -- which could account for the problem of seeming to have too little heating. On the other hand, you reference the problem being more at night, so maybe not.
The fundamental problem is that the circulating water isn't hot enough to satisfy the heating requirement, and we'd need to know more about your system -- amount of radiation, flow, actual temperature settings, etc. -- to be really helpful.Br. Jamie, osb
Building superintendent/caretaker, 7200 sq. ft. historic house museum with dependencies in New England0 -
will try to gather all of that...I am not that saavy as I am a single woman with a house to maintain so am learning as I go...I will get that info though as I am good at researching "how" to find it.. thanks!0
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Is the thermostat in the room that is cold? On the same floor? Is the boiler constantly on?0
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I sometimes go for the obvious questions so please don't think I am talking down to you just asking. Do you have a programmable thermostat? Is it programmed for setback and maybe you didn't realize? On another note you are correct the sensor should be on the north side in a shaded area, but as Jamie already said that wouldn't make it act like that at night more likely during the day. Of course if you are using setback and it's getting solar gain that would make it very slow to recover during the day.0
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This may not be easy for you on first try, but if you could tell us what the parameters on the the outdoor reset are, we may be able to help.
There's a YouTube video on how to set up the FW 200 control. Watching that may help or you could request the installer give you the settings - if they know them. What they're telling you is a crock: the boiler should have been sized, installed and set up to meet the heat loss of the house.Bob Boan
You can choose to do what you want, but you cannot choose the consequences.0 -
Listen to @ironman, the installer was responsible for installing a heating system that would heat the house. If he does not want to make good, ask him how he would like to respond in court.
There is no excuse for this kind of problem.
BobSmith G8-3 with EZ Gas @ 90,000 BTU, Single pipe steam
Vaporstat with a 12oz cut-out and 4oz cut-in
3PSI gauge0 -
... I do have programmable thermostats... each in same place as when the house was built ... one on first floor and one on second...I did initially think that maybe they were programmed for setback and I would have wanted to try that for gaining some savings... they are not...were first both set on 70 degrees and were keeping up... now only the upstairs maintains the setting... when the heating season began... installers changed both new thermostats as I had issues with both and afterwards it seemed to be problem free... I live on the south shore of Long Island NY... temp downstairs will drop when we are in this unusual deep freeze... then... will either recover during the day.... very slowly or not at all as is the case today... Just to see what would happen... I set it to 76 this morning before work... came home... was 68 and now only 69 degrees at 11pm!...I have been reading and trying to figure this out on my own ... with research online and then found this site... Thank you all for your suggestions... I LOVE the systm otherwise and researched info before buying this system... had natural gas when we moved in and then converted to oil as my brother owns an oil company... got too expensive and needed new system so switched back... NEVER had this problem before..0
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Jamie... if you can tell me how to check for the settings, Radiation and flow... I will find out what they are... actually have the manual but its getting late now... Wanted to add that I have been getting estimates on new windows... insulation... but I really can't afford those things and am not sure that would fix my problem... system should heat the house even if it does cost more...i have a fireplace in the living room which is where the thermostat is....i know that causes heat loss but just got my first chimney pillow/balloon...will help but I know its not the answer..0
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Ironman... how does one determine the heat loss of the house?.. after deciding on the Bosch greenstar 151... and getting several estimates and opinion... I was advised it was a good system for my home which is a 2 story colonial... approximately 2100 square feet... some of which is 2 car garage.. which is not heated...how can I find out the parameters of the outdoor reset?... have seen the video on the FW200 control and kinda think I can get those readings tomorrow... as it's late now...by the time I figure it out with the help of this site I may be an expert!! or at least figure it out and understand how it operates!.. Thanks everyone!0
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It sure isn't a small boiler issue, you've got probably twice the BTU you actually need.
The FW, if it wasn't set up correctly you will have all the issues you're describing.
What temp is the boiler working at (and please mention the outdoor temp as well).
When you have baseboard the settings need to be changed and a minimum temp selected.0 -
only reading i get when I open the flap on the unit... which is where th FW is located,,,, has date and time and "no function"... press the knob abd it tells me the outdoor temp is 16 degrees...reading the manual to find out how to find out what the baseboard setting is... by the way.. thermostat downstairs is set to 77 and actual temp is 67... baseboards are hot and upstairs set to 70... is at 70 degrees..I think at the very least I should the installers move the outdoor reset control to the north side where it belongs...and then call soemone else to properly set controls... what is your opinion?0
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Sorry, not the fw, the boiler temp I think is to the right of the fw. It's green, can't miss the nunbers.
On the fw, we call the dotted circumference of the screen the Race track", is it dotted on the day hours only or dotted all the way around ?
The small dial/knob, is it pointed to the sun, moon, snowflake or auto?0 -
Ahh I have a pic so we can all follow along.
Also, where is the big know that has the radiator icon, the left dial? You're gonna want to max it.0 -
brb... going to check right now..Well... I know what u mean and have seen the "racetrack" in the past.... nothing now...the left dial is only set to #6... when I open the flap... only reading is outdoor temp which is now at 28 degrees and the temp on the unit itself is fluctuating and is at 150... both zones are apparently on as the red lights are on0
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I would do just that. When GW gets done explaining the unit controls to you. You can call the installer in to give him a lesson on setting up the boiler he installed.ant930 said:I think at the very least I should the installers move the outdoor reset control to the north side where it belongs...and then call soemone else to properly set controls... what is your opinion?
It makes my blood boil when someone makes up excuses for their own short comings.
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by the way... in looking at the manual operation is with "closed flap" why do the controls look more advanced in "open flap"?0
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local news and weather says 19 degrees... I no longer have an outdoor thermometer
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appreciate everyones help... can always tell when someone is making up excuses for their own lack of knowledge...always do my homework even though I may not fully understand what it all means... at least its a little bit of ammo...lol0
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never mind about the closed and open flap question...lol... anyway.. GW,, the dial is on the sun icon0
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The heat loss is determined by doing a heat loss calculation such as an ACCA manual J or equivalent.ant930 said:Ironman... how does one determine the heat loss of the house?.. after deciding on the Bosch greenstar 151... and getting several estimates and opinion... I was advised it was a good system for my home which is a 2 story colonial... approximately 2100 square feet... some of which is 2 car garage.. which is not heated...how can I find out the parameters of the outdoor reset?... have seen the video on the FW200 control and kinda think I can get those readings tomorrow... as it's late now...by the time I figure it out with the help of this site I may be an expert!! or at least figure it out and understand how it operates!.. Thanks everyone!
SlantFin has a free heat loss calculator that you can download from their site. You have to take measurements of your walls, floor, ceiling, windows and doors and then input that into the program and it will calculate the heat loss. You can probably do it in a couple of hours. Your contractor should have done this to determine the size of the boiler and the settings for the outdoor reset curve.
If you have baseboard heaters, their output is cut to about half @ 150* supply water from what it would be at 180*.
The function of outdoor reset (ODR) is to adjust the supply water temp to match the actual load based upon the outdoor temp. If it's not set up correctly, then it may not be supplying hot enough water to your radiators.
Your old oil boiler probably did not have ODR and only supplied 180*+ water continually. It may have been set even higher if you're under-radiated.
The problem you're having is most likely the setting of the ODR curve on the FW200 control. If your installer adjusted it at all, he didn't get it right. I'm doubting that he did anything with it and it's probably set to the factory defaults.
There may be other issues, so if you could post some pics of the boiler, its near piping and controls, that would help.
Bob Boan
You can choose to do what you want, but you cannot choose the consequences.0 -
Ok, email me back if you want a tour of the settings, I cant type all this out. You need to get into programming0
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@GW.GW said:It sure isn't a small boiler issue, you've got probably twice the BTU you actually need.
The FW, if it wasn't set up correctly you will have all the issues you're describing.
What temp is the boiler working at (and please mention the outdoor temp as well).
When you have baseboard the settings need to be changed and a minimum temp selected.
Gary, if the installer used the onboard circ to directly pump the house, then she's only gonna get about 40k btu's because it's a 4gpm pump.
Bob Boan
You can choose to do what you want, but you cannot choose the consequences.
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With the line of BS the OP was given you gotta wonder about the whole install.
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Im going to try to take some pics...and post them... am leery to touch anything that I don't know about.... wish you guys were in my area!.. just wondering.... how much does the fact that the outdoor reset is placed on the south.... directly behind the boiler room and under the area where the gas exhaust exits... have an impact on this whole mess?... in addition to the settings probably being wrong?0
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Whaaat? You gotta get a pic of that sensor location please!0
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lol... k.... at the moment am trying to attach pics of the system..0
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Have more pics but this site just said I have a "spam block" cause I postd to quickly?...0 -
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Ironman, it didn't occur to me the system could possibly be that poorly installed. Here is a shot of our typical wall hanger, we use a simple 2" header.0
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Can you snap a pic a with the camera higher up, about level with that higher circulator? The sprivent is curiously installed
Other items are less ideal, you're not supposed to have circs with the motor going down or up. I'm sorry to say it looks like a non heating pro installed this system0 -
I'm really curious if my understanding is correct about the outdoor sensor location.0
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I don't know whether you have already seen this, but working with GW this may help.
https://www.youtube.com/watch?v=EMboIQYGVvg 0 -
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GW.. I will take another pic higher up... BrB0
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Well it's p/s.
How much of the piping was existing, and how much did he change?
If it worked before we think about what has changed.0 -
by the way... temp downstairs is now 71 degrees... .. crazy!... upstairs always fine..0 -
Okay not what I was picturing so that's good. But would still move to the north side. Do you get much sun in that location, or is it shaded?0
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