Welcome! Here are the website rules, as well as some tips for using this forum.
Need to contact us? Visit https://heatinghelp.com/contact-us/.
Click here to Find a Contractor in your area.
3 questions
remodel
Member Posts: 68
1) Is it worth it to put in a smaller boiler pump and smaller system pump? Boiler a loch 155. Right now I have about 8gpm to the system and 8gpm to boiler all zones calling. One zone calling I have 4 gpm -5gpm to system and 8 gpm at boiler. At 30%-50% fire boiler DT good, at 20% - 7 degree DT. System oversized by 25% so might be a moot point.
2) Can I put cast iron rad/panel rads in place of fin tube BB at the end of my series loop or will I rob too much heat? I would have to pipe it in series and this loop has one FCU off of monoflows right after rad replacement. The remove and replace is about 50%-60% of the 1st floor emitter length.
3) Is negative DT alright at start-up?
2) Can I put cast iron rad/panel rads in place of fin tube BB at the end of my series loop or will I rob too much heat? I would have to pipe it in series and this loop has one FCU off of monoflows right after rad replacement. The remove and replace is about 50%-60% of the 1st floor emitter length.
3) Is negative DT alright at start-up?
0
Comments
-
3 questions
That boiler needs 15 GPM to operate properly and safely at full fire.
At 8 GPM and full fire you are damaging the boiler.
Yes you can install cast iron rads at the END of the fin tube loop. cast iron rads will operate at 160*. They will have a different heating characteristic. But why do you want to do this?0 -
boiler pump
1) thing is I never have full fire (oversized) and I limited her to 80% max for SH. Issue was with the oversize and lacking emitters I get pretty hot return water and delta t was at 3 degrees so we reduced the speed to 1 on a 15-58. On design day she went up to 65% and modulated down to 30%-35%. Should I even bother to mess with this pump or just leave it and try and get best condensing with ODR?
2) One long run (~20') of fin-tube likes to tick. Even with ramp delay and a pretty nice ODR. Just thought maybe CI BB would alleviate this.
3) Any thoughts on the negative DT for 10 sec...is that alright? Thanks.0 -
Firetube
It sounds like you have a WHN (firetube) model? Please confirm as it is important when it comes to low rates.
Generally, mixing and matching cast and copper in the same loops make it more difficult to balance the room heat. One is high mass and one is low mass, this can create issues.
Is the boiler sending an error regarding the negative delta t or is it something you are observing? It could be a sensor that is out of spec. What is the difference in temp? They should be about the same at startup.
Carl"If you can't explain it simply, you don't understand it well enough"
Albert Einstein0 -
yep WHN
1) Had some piping issues (that are fixed now, PONPC and air) just trying to get this sucker dialed in as best as possible, I have not had any lockouts since repipe.
2) Any tricks to eliminate that ticking BB?
3) DT of 0* then observe -1* max and she comes out to 6*-7* DT. Setting boiler pump on speed 3 gives me a DT of 3*. Is it just what it is. I will say I did choke the outlet ball vale on the boiler pump and got a much better DT at the boiler but outlet temp increased looking like she would short cycle?
0
Categories
- All Categories
- 86.3K THE MAIN WALL
- 3.1K A-C, Heat Pumps & Refrigeration
- 53 Biomass
- 422 Carbon Monoxide Awareness
- 90 Chimneys & Flues
- 2K Domestic Hot Water
- 5.4K Gas Heating
- 100 Geothermal
- 156 Indoor-Air Quality
- 3.4K Oil Heating
- 63 Pipe Deterioration
- 916 Plumbing
- 6K Radiant Heating
- 381 Solar
- 14.9K Strictly Steam
- 3.3K Thermostats and Controls
- 54 Water Quality
- 41 Industry Classes
- 47 Job Opportunities
- 17 Recall Announcements