WarmRite System - No flow

WarmRite_Newbie

Hi, we recently moved into a house that has a warm rite in floor system, fed by a hot water tank (potable water). When I followed the previous homeowners instructions to start the system in the fall, everything seems to function except I don't record any flow in the flow meters even when the pump (grundfos UP15-18 B7) is running. I've purged the system and checked the pump (impeller spins fine). I'm guessing I still have air somewhere in the system, do I just keep pushing water through with the bleeder valves open? I get some slight water and bubbles periodically with the bleeder valves open, sometimes an irregular trickle of water. Any other suggestions, or do I just keep purging? Is there a typical time it should take to purge the whole system? Basement floor system house if about 2,000 sq ft. 2 manifolds with 3+4 lines connected together. Can send pics if that helps. Thanks.

hot_rod

a concrete slab can take some time to ramp up, how long has it been running?

A quick check is to measure temperature at the supply and return. There should be a temperature difference, could be as little as 5or as much as 30 degrees.

If the system worked before and no water has drained, pressure is always at 10 psi or more, it should not take a lot of purging to get it back running. What is the pressure now?

How much water drained when you checked the impeller, did it have isolation valves?

Is the pump motor hot to the touch? The is an indication of an air locked system.

Any strainers in the system? All valves open? Hw tank is heating?

Yes to pics

WarmRite_Newbie

The photos show the system layout… I have it set up to do a purge/refill this aft so that is why the green hoses are connected (dark green feed line into return valve from cold water potable supply; light green drain line from supply vale per the WarmRite instruction manual).

Not too much water drained from impeller when I removed it; no isolation valves but I drained the manifold before taking the pump apart. Impeller spun freely and seemed nice and clean. No strainers that I identified; all valves open (though I have closed all as well); HW tank is definitely suppling hot water (when draining from return line into flow drain, get fresh flow of hot water). Pump is warm to touch when running. No pressure value to indicate pressure before or after pump; only indications are flow meters on each line.

If I open the supply line (insulated line in pics), and drain from return line (instead of going to pump, I can get flow up to 4 L/min). When I close return valve flow goes to 0 and doesn't change when pump activated. Air bleeders do pulse when water flowing, with very small air bubbles from time to time.

Next steps at this point to full purge system with new water and try to clear any air pockets through bleeders and loosening front screw on pump, but any tips/suggestions are welcom.

Kaos

You need an air seperator or at least an air vent on the high point before the pump. As it sits, air can collect there and you can loose prime on the pump.

You also mentioned open loop. How exactly is this setup? Open system and stagnant water for 6months is a bad idea.

hot_rod

you need a valve at the supply manifold to keep water from going backwards.

Flow through manifold, around loops to purge valve on return.

White caps on supply need to be loosened, or removed to open the manifold ports.

Ironman

You need to purge each loop individually with the other closed off. You can do that by turning all the white caps closed except the one you’re purging. Then, close that one and move to the next, etc.

Your pics don’t show what type of fill valve you have, but if it has a bypass that allows you to increase the pressure to about 25 psi, you’ll get better results. Don’t exceed 30 psi or the relief valve will dump.

Once all loops are properly purged, open the white caps.

WarmRite_Newbie

Thanks all for the suggestions. The only one that may be a challenge is the shutoff before the pump. Will do the zone/line purging and see if that does the trick… the previous owners (presumably) used this for 20 years with the current setup, so there must be a solution. Appreciate the tips above!

For context, "open loop" refers to it being applied buy a HWT, not a dedicated boiler, and so has some risk of air entrainment form the HWT (since they generally have an air space at the top. I also think the main shutoffs at the inlet/outlet are a bit far from the pump.

No bypass in the fill valve, its a standard ball valve (4th photo above).

mattmia2

Besides the possible legionella and other bacteria breeding in it, since there is constantly fresh water in the system, that water will have air come out of solution as it is heated so it will tend to make the system air bound unless there is automatic air elimination as @Kaos mentioned.

There may be an automatic air vent that is closed off as the minerals from the fresh water will tend to make it scale and leak.

Kaos

Does this tank also supply your DHW?

You can probably get away with replacing this elbow with a T and an auto air vent.

Ironman

Some clarity would help. Is the water heater also heating your domestic water?

If so, is there a heat exchanger between the water heater and radiant floor or is domestic water going straight to the floor from the tank?

hot_rod

https://forum.heatinghelp.com/discussion/comment/1872752#Comment_1872752

every wider angle picture tells a story, don't it

WarmRite_Newbie

Still battling with my system… quick question, should there be water coming from the bleed valves on the top left of the supply manifold, or is this a sign they are plugged and not doing their job?

WarmRite_Newbie

Sorry, just seeing the other posts… I have 2 HWT that supply potable water, WarmRite, and support my heat pump. Domestic water going straight to the floor system then returning back to the 2nd HWT.

The only air vent I see in the system are the 2 bleeder valves on each manifold, which have some mineralization but per previous post are currently expelling water when I purge the system - so perhaps aren't doing their job? I think they are too low in the overall system to be of much use.

I think t'ing off above the pump and putting an air valve there is my next step. Have a similar configuration on my furnace/heat pump (see photo).

hot_rod

those small float type air vents are mainly used at high points in the system. They are not much use on a pipe with water flowing. You need an air purger for that

Since there are no white water deposits on that vent, either there is no air or it is not functioning

Typically you see indications if a vent has been spitting air/ water

There needs to be pressure and water at both air vents on the manifold

If the system is not filled and purged- no circulation and no heat

Got a pic of all the piping?

EdTheHeaterMan

Can you step back and take some photos of the entire system and near boiler piping? Trying to diagnose with those close up photos is next to impossible.

Example:

My tire will not hold air pressure! Is this the right place to add air pressure to my tire? I have been adding air for about an hour (I think) but no air is staying in the tire. Could the valve be blocked?

The photo below will tell more of the story:

EdTheHeaterMan

Here is an example of a complete system photo that I was able to match to the manufacturer's suggested design.

You can see how all the components are connected in the big picture

hot_rod

An "open" combined system is one where both the radiant and DHW is one and the same. Not highly recommended. I don't recall WarmRite ever promoting those systems.

If there is a fill valve, pressure reducing valve, connected it is not a combined system.

Although the stainless circulator could point to a combined heat/ dhw system.

IF it is a combined system, it should purge in minutes as you have house water pressure doing the fill/ purge.

It's possible to have a standard DHW tank connected to the radiant, it would still be a closed loop dedicated HW tank system.

Or a heat exchanger could be on your DHW tank to separate heating from potable?

It would be helpful to see more of your system. Could be just one valve in the wrong position?

WarmRite_Newbie

Here are 7 photos of the system:

1 - Dual HWT with piping

2 - Top of tanks with labels for separate lines

3 - Top view of HWTs

4 - Back view showing runs to/from WarmRite and Water Furance

5 - S/O for lines to WarmRite (instructions from homeowner to close in spring and turn off power to pump/open in fall

6- Top section of feed lines to WarmRite

7 - Manifold

In speaking with a former North American service rep for WarmRite, he indicted that air in the top of the HWT could cause issues (he referred to the setup as an open system, as it is not completely sealed). Also, the two air bleeders on the supply side of the manifold both push out water (and the odd very fine air bubbles) when I am going through the purge process. Hard to tell if they are serviceable/can be removed and cleaned.

My next step is to follow the process (again) from start to finish and try to purge/recharge each of the 7 loops. I did find last time that if I closed one loop before opening another I got a vacuum and flow stopped, and when I tried to open the next valve nothing happened, and I had to start over, turning everything off and opening/closing valves and bleeding the pump.

hot_rod

WarmRite_Newbie

I had the feed (hot water) line off during purging; I supplied water directly from the well instead of using hot water, since I was discharging to the floor drain. I have tried purging with the return line both open and closed, but on my next attempt will follow the procedure in the WarmRite manual - add feed water through the return port on the manifold, and discharge through the supply port on the manifold, while keeping the main return line open after the pump, and will go loop by loop. The one drawback of this is that the individual flow meters don't register flow (assume they are uni-directional?).

Any thoughts on the 2 bleeders, are they potentially preventing air from being purged since they are both full of water, or should I expect any air bubbles to make their way out?

If I can't get it going after one more attempt, I will add a tee and air purger as recommended by @Kaos . Is this what I need to add (vs. the bleeder valve): https://www.homedepot.ca/product/watts-vacuum-relief-valve/1000115772 ?

Kaos

How does heat get into this setup (desuperheater on air handler)? Looks like a fully open system, stagnant loop on well water with no chlorine, you are asking for trouble.

Also see a lot of check valves but no expansion tank.

This falls into the category that somebody that knows hydronics should really look at it. At minimum you are missing a heat exchanger to isolate the heating loop.

That part is a vacuum break, that won't work. You need an air vent:

https://www.supplyhouse.com/Caleffi-502043A-MINICAL-Automatic-Air-Vent-w-Hygroscopic-Safety-Air-Vent-Cap-1-2-NPT

hot_rod

You need to make sure flow goes to the supply manifold, purge the return, with all those check valves flow is one directional.

If you hook a garden hose to supply, a purge hose to the return manifold, you need to turn off both theses valves to assure you are in fact going through the loops.

I's possible the loops are purged you could have some other issue. Closed, plugged, stuck valves?

WarmRite_Newbie

@hot_rod the valves seem to be fine - I have isolated each and had full flow (4 L/m)

@Kaos Hot water supplied by 2 hot water tanks; well water does go through a softener. No expansion tank.

I think the main culprit is the lack of air / vacuum release around the pump - I think the system itself runs fine, but there is a vacuum created around the pump that prevents it from pushing flow back to the return line. I am going to get one of the air vents from the previous post and tee it in at the top-most elbow on the return line above the pump, and go from there.

I appreciate all the input and help - certainly been an interesting process for me!

WarmRite_Newbie

One other question: should I be replacing the bleeders on the 2 manifolds, or trying to clean them? As indicated, right now they are emitting water - is this ok/normal?

Or perhaps I can close the caps and rely on the new air vent to relieve any vacuum?

Ok, that's 2 questions… :-)

hot_rod

If you loosen this screw, or remove it you burp air out of the circulator. Carefully if the pump is really hot, steam may come out!

With the pump powered you will see the end of the shaft spinning with that plug out.

A 15-18 is a pretty small circ for radiant work, it is really a DHW recirculation pump, used because it is a stainless body..

WarmRite_Newbie

I did try that as well, and do get some air release and a trickle of water, but when I reseal the centre screw I don't get any flow. I guess that could be the other issue - pump could be undersized for the system, but I find it hard to believe that the previous home owners didn't realize the system wasn't functioning properly for the past 20 years (previous owner passed away, or he would have been my first call - he generally kept impeccable notes/records for the various systems in the house).

Kaos

The issue is you are mixing radiant heat with potable water. That stagnant floor loop is a perfect spot for bacteria to grow which you now breath in each time you shower. Just because it has worked for 20 years, it doesn't mean it is proper.

There are ways to do this type of open system, but what you have is not one of them. Even the "proper" open systems can be an issue on well water due to the lack of chlorine.

The proper solution is to isolate the space heat like this:

https://www.civil.uwaterloo.ca/beg/archtech/hot_water_heater_furnace.pdf

You can see your setup is missing a lot of the bits required.

hot_rod

https://forum.heatinghelp.com/discussion/comment/1872982#Comment_1872982

With the screw out, was the shaft spinning?

You can build or buy a prefab heat exchanger module to separate as @Kaos suggests

A Utica Boiler module, there are others.

On combined systems one work around is to once a week, all summer fire up the pump for an hour to move fresh chlorinated water through all the loops.

mattmia2

it is a well, no disinfectant…

EdTheHeaterMan

It took some time and I'm still not sure about the part in yellow but I believe this is the setup.  Cold water enters tank 1 cold inlet, then goes from tank 1 hot to tank 2 cold and exits tank 2 hot to feed DHW to the fixtures.  Hot from tank 1 goes to the radiant floor heat.  As a result of the check valves (I know they are spring checks and I used swing checks in the drawing) to purge the radiant tubing I believe you need to close the valve on the return from the radiant tubing after the circulator pump to purge that air from the system.

So this photo should look like this

I know that this will waste hot water, but it will be the best way to purge the air from the loops. And you only need to do it once to get the air out. And you can turn off the water heaters so it does not make any more hot water until you have all the air out.