flow issues, again

Sukhoi29SU

Open M-SHEETS_DAS_2021-02-09_Rev 1 2.pdf

It's that time of year again when the temperatures drop to single digits in northern Illinois and I'm stuck troubleshooting a hydronic system that was installed a few years ago. My wife has resorted to utilizing the heat pump on the A/C unit in order to try and keep the temperature closer to the thermostat setting - which is extremely inefficient in single digit temps.

The system seemed to be performing ok with temps in the low 30s or high 20s (reference a post that I made a couple weeks ago about water color where I felt that the system was performing adequately), but now that the temps have dropped considerably - the system just doesn't keep up.

Bottom line - I'm not getting the design spec'd flow rates through my floors - And I think this is the underlying issue. Why the lack of flow? The design (attached) has been questioned from whether the boiler low loss header should be utilized or not, properly sized pumps or not, etc. The one thing I've never felt confident in is the water quality, though. When the system was installed the local company that I hired to hook up all of the copper opened up the valve to the new system (well water with a newly installed well pump) and introduced unfiltered water. Needless to say I was disappointed. I believe that the new well pump picked up a bunch of crap from the bottom of the well and allowed it to infiltrate the pipes. The attached picture shows some of the stuff that I've found in the water when I open up the bottom of the Caleffi hydraulic separator. I've taken out and cleaned the filter bowls on the supply line side of the taco 3 way valves countless times and have routinely found them to be mostly obstructed. I will say, however, that this year I haven't found them to be as clogged up as in the past. I still am only able to get roughly .2 gpm on the uponor flow indicators at the manifolds at the peak flow. Then it slowly resorts to barely any flow after a few hours or so. I've set the pumps to max perform vs. the auto adapt feature - to ensure I'm getting max flow possible.

I think what I need to do is start with new water to completely rule water quality out. I started to listen to @hot_rod in a "coffee with caleffi" about purging and filling hydronic systems from 2013 and plan to finish listening later. I sure wish that the local company that I hired a couple years ago would have had this knowledge, followed the design plans to a T, or simply would have been more competent.

Question: I found a Caleffi Hydrofill NA5709 video on youtube - and with the amount of money and time I have invested into this system - figure something like this would most likely be money well spent. I think I need to get the existing water out of the system completely, clean the system with a cleaner, and put properly filtered, proper ph water in. It appears that supply house no longer carries the NA5709. Are there any recommendations to something similar? I will then plan to treat with fernox f1 inhibitor per design spec.

Eventually this system will implement an indoor Switzer wood gasification boiler as the primary heat source, with the Bosch propane boiler kicking in as a backup. Looking forward to simply getting the system working consistently and properly with the Bosch boiler before complicating it any further.

Thanks in advance for any recommendations.

GroundUp

The design is not attached, and it's nearly impossible to see what's going on with the piping or what it's trying to heat. Yes the hydraulic separator should indeed be there, but it looks like you have the circulator isolation valves throttled and/or closed. Why? What is the system pressure? What are you trying to heat with what sort of emitters?

Intplm.

Your thoughts on starting with new water are spot on. Flush and purge the entire system and make sure you empty and clean the dirt mag.

You have valves that are off or throttled. Why? Open them and let it flow.

Your well water is of some concern. I am wondering if over time it has caused the debris that you show in the picture. And because it is a well, do you have enough water pressure to purge and clean the system? Find out what your water chemistry is and go from there.

Sukhoi29SU

@GroundUp The pdf of plans - I’m showing is attached?

Ignore the position of the valves - I attached this picture just for a big picture look at my system setup. This picture was taken last year when I was troubleshooting. the top left valves are actually closed because those are for further use when the wood boiler is connected.
I had modulated one of the valves while troubleshooting - it’s back to being fully open now.

I have a constant pressure system attached to the well, I want to say it’s set at 60PSI right now - it should be plenty of pressure to purge the system

GroundUp

I asked for the system pressure, not the well pressure. What are you trying to heat with what sort of emitters?

hot_rod

if you suspect clogged components coated out emitters, etc.

Add a cleaner to what you have. Then you. Need a power flush, enough gpm to get a least 5 fps velocity in every pipe nd component. A good brand hydronic cleaner, not dishwasher soap.

Generally a 1/2 pump cart capable of 13 gpm, or so for residential systems.

By using a cart, you will see what, and how much flushes out. Also just keep the cleaner running through the pump cart at those high velocities. With a garden hose you are not running the cleaner across all the surfaces, over and over.

You want at least 3/4” hoses to connect into the system to get those flow rates.

For a DIYer a garbage pail and a 1/2 hp transfer pump, a spa pump, used pool pump, something that pushes good flowrates.

Sukhoi29SU

@GroundUp sorry, I was answering Intplm’s question about well pressure.

this is a radiant floor system. There are two European style wall radiators in the kitchen, but the rest is 1/2” pex - majority in concrete. On main floor I utilized approximately 1600sf of sunboard. Total: Approx 4100sf of house, and 1700 sf garage and additional 1700sf of workshop beneath garage.

A Bosch FS-151 propane boiler is current heat source - 135k btuh. Eventually hooking up 200k btuh wood boiler to system.
Plans re-attached here.

Are you asking about the pressure indicated on the front of the boiler ?

M-SHEETS_DAS_2021-02-09_Rev 1 2.pdf

Intplm.

I believe he is asking about the system pressure showing on the front of the boiler.

And as to the well tank pressure. Yes, 60 psi is plenty for purging as long as the pressure switch is set at, in your case probably 60/40 psi.

The debris that you are seeing can be caused by a few reasons. The water could be deteriorating rubber or other material/metal parts that are then flowing through the pipes.

Is this happening anywhere else or only in the heating system?

If just the heating system that needs the most attention. You will need to figure out why this material exists in your heating system and eliminate it that issue. That type of debris will commonly get stuck at transition fittings where there is a choke point.

Sukhoi29SU

@Intplm. thank you. I believe it’s only in the heating system. I wish I would have listened to that podcast by hot rod before they filled the system with well water a couple years ago. Firstly, it should have been filtered prior to just opening a valve to the well. Secondly, I wish I would have used a cleaner to clean all of the new components. I think I might get through the next few months with the way it is, and then put new water in the system over the summer. I have two wood burning stoves and a heat pump as secondary and tertiary heating options. This radiant heat will be fantastic when everything is working correctly, but so far it’s been a lot of problems and troubleshooting. I think the system might be a little over designed, as well. Sometimes simpler is better...

Sukhoi29SU

@GroundUp