Boiler not getting to set temp

dpetrocik

2015 Weil McLain cgi LP boiler system that was put in by previous owner. Worked well for in floor lower level heat and registers in the upstairs room. It also had 2 indirect water tanks for the domestic hot water (one big, one small). Had some issues keeping up when it was -15 degrees out in our Michigan winter months. One of my indirect units started leaking to I took it out of commission and just closed off that zone. I decided to take out the other zoned water heater as well and installed a tankless unit for the domestic hot water. So I have essentially deleted 2 of the zones so now the boiler will just heat the house. Well it’s now getting cold out at night so I fired up the boiler and set it around 180 degrees, however, it will not get above 128 and runs constantly. Any idea what’s causing this issue?

Thanks!

STEVEusaPA

Not enough water in the system and/or circulator not working are the first 2 things to check.
You mention 'boiler' and 'registers'. Is this a hydro air system or are you calling convectors (baseboard radiators, etc.) registers?
Why 2 indirects? Are you sure one wasn't a buffer?

Jellis

It is odd to me that you had 2 Domestic water tanks. Are you sure one was not a buffer tank for your heating loop?

do your convectors get warm to the touch upstairs (sounds like you have radiant floor heat on the first floor, the 2nd floor? baseboard or radiators?)

If you had a leak your system may be low on water or air bound.

Pictures of your system may help, did you do the work yourself? or did you hire a professional?

dpetrocik

The upper floor is baseboard, sorry for the miscommunication. The small tank was a buffer for the larger tank (original set up had two separate zones and aqua stats for the tanks and the small tank fed directly into the big tank) the small tank was the one leaking and I removed it from service and just used the large one for the domestic hot water. It was used up until the day I switched over to the tankless unit. The boiler system itself now has 5 zones, one being in floor heat. All I did when removing the two tanks was shut the valves going to those 2 particular zones assuming the rest would still run as normal. The system does have an expansion tank, auto air bleeder, auto fill, etc. Also, the pipes leaving and returning to the boiler itself are hot and the circ pumps are also very hot to the touch.

JakeCK

Pictures?

dpetrocik

I’m at work, but these are the tanks I took out. They were in tandem with each other. The small tank would act as a normal small water heater and then it was connected to the larger tank. I actually took the small tank out of commission part way through last winter and just ran with the larger tank. All it did to my knowledge was make us run out of hot water a little quicker. Late last night I did feel the pipes for each zone and on one of them the return was cold even though the Zoe was Calling for heat and the supply or delivery to the zone was hot. I’ll purge it when I get home. Not sure if that is the root cause of the temp issue though.

dpetrocik

The small one very well could have been a buffer of some sort but the system ran perfectly fine last winter without it? And like I had mentioned. It was set up exactly like the larger tank and connected to it as well. When I removed the small tank was my large indirect acting as the buffer tank then?

HVACNUT

Is there outdoor reset? If so, the limit is 180° but with mild outdoor temps, the boiler only needs 128° to heat the home.

dpetrocik

> @HVACNUT said:
> Is there outdoor reset? If so, the limit is 180° but with mild outdoor temps, the boiler only needs 128° to heat the home.

I will take a look after work! Didn’t think about that. The outside temp was around 50 last night

hot_rod

The burner is firing and it doesn't get over 128F? Or it turns off at 128F?

If it runs non stop at full fire the energy is going somewhere.

dpetrocik

Quick update, finally had a day off and time to mess with it. Started with the easy thing first, bleed/purge. I did all of my zones and there was definitely air in there. After I did that I turned it on and it fired right up and went to set temp and **** off, looks like it’s operating fine and there was just air in the system from when I took out the two tanks. Thanks for all of the recommendations and input!