Can't get enough heat out of my system!?!?

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perchin

perchin

Member
Nov 30, 2010
126
Hey guys,

I recently got a Ridgewood Model# 6000 OWB. I installed it myself, and later had the company's installer come out to help diagnose the problem. He said I installed everything correctly and very cleanly. He left dumbfounded that we could not get the system to heat my house. I have a hard time believing this. Please note that our Side arm is working just fine, and in fact I have yet to run out of any hot water. The electricity is off to the hot water heater, and has been for a few days now.

Some background. The pump on the OWB is a Honeywell model# PC3F1558IUF00.
It is a 3 speed pump, and the Manual says that it has a maximum flow rate of 15GPM on high speed (which I have it set on)

I am running a 32" Sidearm, which is 3/4" inside 1 1/2".

The water to water heat exchanger was included with the OWB purchase and does not display a brand name. It
just says the following " 50-RD40 Capacity up to 300,000 Btu/h @ 30.7 GPM PD<5 psig

The houses Boiler system is a Slant/fin boiler with a Grundfos Type UP 15-42F pump. The thermostat for the water temp. was previously set a 200° (seemed really high to me)

There is approximately 140ft of 3/4" copper pipping of which 90ft is baseboard with fins. According to the front gauge on the house boiler the pressure in the lines is at about 20 to 25 psi.

The house has a total of 1,638 sq ft. to heat. We can not get the house above 60°F without the help of our pellet stove.

There is approximately 75ft of insulated 1" Pex tubing running from the back of the OWB to the house 6ft under ground. Once in the basement, it immediately 90°'s and runs 10ft through another wall where it takes another 90° turn towards the Sidearm. It then takes two more 90° turns into the Sidearm. From the side arm it travels less than 3ft through 2 90° turns into the water to water plate exchanger. Then it leaves the plate exchanger and goes through 4 90° turns back to the OWB.

The guy who came out from Ridgewood bumped up the High Set Point to 200° from the pre set 180° and said it should help. Well it has allowed us to only get the house up to 65° and that is running 100% everything on high.

When we had propane, we could get the house to any temp we wanted, although we only used it for only one winter because it went through so much propane. The system has sat empty for the last 6 years, until this install. I have already got all the air out of the system... have bleed it about 10 times now to make sure.

Someone school this dummy why this set up is not working??? I see right off the bat that the pump is only capable of pumping half of the GPM that the exchanger will take, but am not sure if this is the problem. Any help would be more than appreciated.

Below are some photos to help describe my setup.




Where the pex enters the house


Then into the furnace room


And inside the furnace room

 
Have you measured the water temp leaving the boiler and temp when it reaches the house ?
 
Not sure how I would go about doing that? I could measure at the stove based on what the aquastat says but where in the house could I get to the water without cutting into the pipe?
 
perchin said:
Not sure how I would go about doing that? I could measure at the stove based on what the aquastat says but where in the house could I get to the water without cutting into the pipe?
Click to expand...
strap on thermometer on the incoming pipe. Could even tape regular thermometer or an outdoor thermometer sensor to the pipe with some insulation around it,
 
Sounds like your piping is just not large enough to carry the flow you need. Counting each elbow as equivalent to 4' of straight pipe, your round-trip loop adds up to something over 200'. Plus the sidearm. Plus the WWHX. The pump you're using can probably only push about 5 gpm under the circumstances. BTU per hour is deltaT times gpm times 500, so try to get an estimate of what your deltaT might be by measuring supply and return temperatures from the boiler with system gauges or a hand-held infrared thermometer.

Short term you can go with a bigger pump with a steeper curve, a Taco 0011 for instance. You'd be going from 85 watts to over 200 watts, so if your're running it most of the time you'll see it in your electricity bill, but it should just about double your gpm.

And your WWHX is likely undersized. "Up to 300,000 btu / hour"? They might as well say up to 1,000,000 btu per hour for all the difference it would make to your actual system. [As noted below the WWHX could be your main problem, but we need more temperature data to have a better idea.]

Longer term you could move you WWHX over to where you OWB piping enters the house and then use a small pump to move the water through the sidearm and other loads. This would lower the resistance of the OWB-house loop considerably.

Even longer term you can start installing some panel radiators or other low temperature emitters to increase your system deltaT.
 
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Are you saying to strap the thermometer to the pex? Curious because the pex and the brass fittings in the loop are at very different temps to the touch. The pex is uncomfortable to touch and the brass is even hotter.
 
An IR thermometer (gun type) would be very useful here, long as it's a decent one. You should be able to get temps off the fittings - the el's as soon as it comes into the basement are good spots. You might have to spray a splash of flat black paint on the surfaces you're trying to get temps from - IR guns don't do very good on shiney surfaces most times.

Without lots of temp data we can't really suggest much. Should measure the temps at OWB supply/return, same where it gets into the basement, temps at each HX in & out - both sides, and supply & return of your indoor boiler. But what is the temp in your indoor boiler? Should be a guage on it? Also don't know much about your house. If the baseboard was designed to meet heat load with a water supply temp of 200 (where it was set at), with no extra capacity designed in, you might need more radiation also.
 
aahhaaaa... I will paint them then. I already have a IR thermometer gun. I'll check back asap...
 
Ok... I tried painting the surfaces that I was trying to monitor the temp on... I'm still getting pretty crazy readings that are jumping all over though. I just put a meat thermometer on the surfaces long enough to get a steady reading with it, and here are the results.

This is where the pex first comes into the sidearm (which is the first thing in the loop) about 195°.


Here is where it first enters the exchanger approx. 192-193°
 
perchin said:
Ok... I tried painting the surfaces that I was trying to monitor the temp on... I'm still getting pretty crazy readings that are jumping all over though. I just put a meat thermometer on the surfaces long enough to get a steady reading with it, and here are the results.
Click to expand...
Pretty sure it's the other end of the needle that matters. The meat thermometer might work nicely but I think you would need to lay it along the pipe near an elbow and then wrap the needle end with foam sheeting of some sort so the temperature in the space under the foam comes up to the temperature of the water in the pipe.
 
ewdudley said:
Pretty sure it's the other end of the needle that matters. The meat thermometer might work nicely but I think you would need to lay it along the pipe near an elbow and then wrap the needle end with foam sheeting of some sort so the temperature in the space under the foam comes up to the temperature of the water in the pipe.
Click to expand...

No, but thanks. the round end is what matters according to the original packaging, and from experience using it to get my perfect medium rare steaks on the grill.
Not saying it is perfectly accurate, but the IR gun was just ridiculously jumping around on temp.
 
I was thinking the same, I think the pointed end is what you go by ? as ewdudley said, need to wrap some insulation around it
 
What is the temp coming out of the flat plate then ?
 
What's the temp at the OWB while you're doing that?

And what does the thermometer read when it is just sitting touching nothing?

The picture of that thermometer on the Taylor website just sitting there not measuring anything has the bubble end of the needle at 190. I think you are using the wrong end of the needle. Stick it in some boiler water if you want to find out for sure.
 
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Maybe it was a Monday thermometer.

I don't trust my IR thermometer, but usually if I paint the surface with flat black BBQ paint, and hold the IR gun right up against it, I can get stable somewhat sensible readings. To use the meat thermometer, as said, you need to get the probe flat against the surface as you can & hold some insulation around the whole setup. Just holding the point or stem on the surface will be pretty inaccurate.
 
Just a thought that you might want to move the sidearm to the return of the flat plate. That way the hot water from the own hits your big load that needs higher temps first, but there should be plenty to heat dhw still. And there is a tempering valve on your hot water heater, right? RIGHT?!?!?!

Can your house pump handle the flow through the HX? Do you know its pumping? If it sat for years it might just be stuck not spinning. That could explain some of the issue...
 
Ok... This is just not working out. I'm guessing I'm not actually getting the water temp while doing this right? Where exactly can I get an accurate temp. Every surface throughout the system is at FAR different temps. For instance, the pex, I can grab ahold of without burning myself. The copper components I can not. Logically the water temp is going to go down as I move down the loop. I just want to know what the actual water temperature is right? Not what the surface of the pex is at? Or is there an equation that is involved, like if the pex is @ 98° then the water inside is @ 148° or something?

I will post a video soon of what I am getting with the IR and walk everyone through what I am seeing.

And as far as the meat thermometer, it might be reading wrong or something... It has never recorded any temps higher than what I took a picture of.
 
maple1 said:
You might have to spray a splash of flat black paint on the surfaces you're trying to get temps from - IR guns don't do very good on shiney surfaces most times.
Click to expand...
Yep, IR guns work great on a flat black surface and ideally a large flat surface, but that is not as crucial as the reflectivity of the surface (flat black). A consistent distance from the sample is important too when comparing temps like this, closer is probably better here, also, centered on the pipe.
I would bet that the copper and the pex just "feel" different due to different conductivity of the materials
 
Nope no equation that I am aware of to tell you temps. The pex will eventually be the same temp as the water inside, its just a matter of the time of contact.

It might be useful to get a bunch of cheap meat thermometers to strap to your pipes. You can put them in boiling water to verify accuracy, then tape them on . that will help everyone figure this out.
 
Also, if you are gonna use the probe thermometer, you will need to tape it to the pipe and cover it with pipe type insulation and leave it there for a few minutes to get an accurate reading. The suggestion to check the thermo in a pan of (just barely) boiling water is a good idea too, verify accuracy.
 
Ok... I can assure you all right now that the pex is not at the same temperature as the brass fittings and no it will not eventually get to the same temp as the water. It has been running for over a week now and I can grab a hold of and continue to hold the pex for as long as I want. The IR reads the pex as a lot cooler then the brass. I can not even think about holding onto the brass fittings in the system. I know fully well when something is going to burn me, and they indeed will. Just touching them leaves a nice little red spot in my finger and burns like crazy.

I did every IR reading the same. With the IR gun directly against each spot.

I couldn't get my camcorder on the phone to work properly, so here are the photos of my findings with the IR on the painted with flat black high temp paint.

This is where it comes into the house. 179.5°. I couldn't get the photo with it up against the pipe, because it was too dark, but I just took a photo of its hold at high point measured.


This is where it goes into the Sidearm. 186°, strange that it reads hotter here than where it comes into the house. Again, different surfaces at different temps as I was describing.


This is where it enters the exchanger 187.5° ...within 2.5ft of the sidearm


This is where the house's seperate system exits the exchanger 176.5°


This is where the water returns into the boiler after running through the entire baseboard system 164.5°


Hard to tell, but the gauge on the front of the boiler says that the water it is getting back is at about 150°
 
I purchased the Redicheck wireless therms from amazon..just attach to any metal fitting, insulate over, and you will have two temps easy to view...
 
I am no expert but since your temps look good and with the other info you provided , it sounds like air..I know you bled 10 times but when we first designed our system, I had a hell of a time bleeding, did battle with air for the first year, finally one of my buddies came over and added a number of self bleeders and Spiro vents. Some systems the way are layed out (designed) they tend to trap air and are difficult to bleed..after we made those changes, things got warmer...
 
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