baseboards bled, but still no heat.

[Diezmon]

Ok guys I've been googling up the wazoo today to try to figure this out.

I have a two zone system, upper and lower. Gas furnace, one pump(Grundfos Type UP 15-42F), two valves(Honeywell V8048E), and baseboards.

here she is:

I thought I had frozen lines but when I bleed the zones water flows just fine. So I followed the procedures to purge each zone and started the system back up.

Well, I still only have heat to PART of the upstairs zone and no heat downstairs. I'm at a loss what to try next. The thermostats are working, the solenoids/valves are working, the aquastat is working, all manual valves are open, PSI is good(15). I can feel the pipes are nice and hot coming out of the furnace but they go into the concrete so it's hard to trace.

Actually, downstairs there is a little in a baseboard about 4 feet from the furnace, but that's it. And, to make things even more fun.. the first floor pipes are in the concrete floor so I can't get to them or trace their exact route! grrrrrrr. I think this one warm baseboard is the first unit off the furnace..

Can it be my pump is dying and can't get the whole system flowing? The thing is so quiet I can't tell if it's on or off.. It's a Grundfos Type UP

15-42F, by the way.

What else can I try???

Thanks,

T-- (thank God for gas fireplaces!)

Please reply to group.. I'm trying to remain spam-free.

[wannabe]

How do you know the thermostats are working, you say you can't tell if it's off or on, (since it runs so quiet)

You claim partial heat upstairs, could it be full heat upstairs? and you are missing the downstairs heat rising?

I saw the picture, what a beast!

my 2cents

[RBM]

If you are sure that the zone valves are opening, check that you have 120 volts at the pump, if so and the problem isn't air in the line, it's possible that the pump is jammed internally or just dead

[Diezmon]

I know the thermostats are working because they properly turn on the system. I've checked and double checked everything with the voltmeter as well.

I couldn't tell if the pump was working, or that's what I meant by the 'thing' ;)

no full heat upstairs.. It's hard to explain but each zone has two physical loops. The upstairs: About 3 feet from the furnace it splits at a T to these two loops to the upstairs. Then, they return to another T on the return loop, just before the furnace. One loop heats up perfectly, the other loop stays cool even though both are fully open... very weird. I _think_ I eliminated the possibility of blockage, since when purging the water flows freely.

In the pic you can see the two loops for the downstairs(the taller two going into the concrete), and the return T just before returning to the furnace.

The downstairs baseboards, also a single zone with two physical loops, stays cold. But, those two pipes coming out of the furnace, into the floor, are HOT.

A beast? I was thinking it was pretty simple.. which is why I can't for the life of me, figure out the problem! ;)

Tim

[Diezmon]

Yep, got 120 at the pump. My guestimate is that it IS the pump.. but how to find out?

Since the one loop always works fine, it's confusing the sh*t out of me :) The one loop that does work is located fairly vertically above the furnace, so I was wondering if it's just the heat rising up and through.. BUT the return is nice and hot too..

Tim

pump(Grundfos

[PipeDown]

With the solenoid valves open manually the pump may still not be called upon to start. You may only be feeling heat due to gravity fed convection of water in the pipes. With both valves open, the pump may not have the capacity to serve both zones, try closing one valve. Turn the thremostat up or down to see if you can hear a relay click in the heater or a difference in the pump noise or vibration.

Sure sounds like the pump is not doing the job. You can check to see if AC is sent to it and you should still be able to tell if it is running by feel or by peeking in a vent hole in its case.

Often the pump motor is connected to the pump impeller by a spring and arm mechanism. It absorbs startup shock when the motor kicks in but if the springs break, the motor will spin but the pump will be still.

The pump motor and pump (impeller) itself should be considered seperately when troubleshooting because either can fail independent of the other even though they look like one unit.

[Commodore Joe Redcloud]

Are you sure you know how to bleed the system PROPERLY? An air pocket could account for one zone working fine and another one being cold.

Commodore Joe Redcloud

[Diezmon]

Well, when I bled each zone, closing its shutoff valve and opening the purge valve, the water coming out was solid and flowing. I let it run for a while, and then bled them again. And yes, I had the supply running. :)

Tim

[Edwin Pawlowski]

This sounds like the most logical explanation. Especially if it has been sitting inactive over the summer things like that tend to pop up at startup time.

BTW, you don't have a furnace, you have a boiler. Furnaces heat air, boilers heat water. Using the wrong terminology will get nothing but disrespect if you go to the plumbing supply house for a part.

[Diezmon]

Thanks for the tip ;)

[Commodore Joe Redcloud]

Did you start at the highest and furthest from the boiler and work your way back? It makes a difference.

Commodore Joe Redcloud

[Diezmon]

yep, I sure did.

[JJ]

Either you have a bad zone valve or your expansion tank is bad.

[m Ransley]

I always bleed without the supply on, fill to your pressure needed cold by the gauge and bleed with boiler off then boiler on, the pump working and a heated boiler will make a difference if its working. It sounds like the pump or zone valve

[Stormin Mormon]

I've never heard of shutting off a valve in order to bleed. I've always done it with the valve open.

[Diezmon]

maybe we're getting our terms mixed up? I'm actually 'purging', which is done from the boiler area. There aren't any bleed valves in any of the radiators of the house.

You close the valve to centralize your purging to the zone you want to work on. so you're purging one zone at a time..

Tim

[Goedjn]

Disconnect the power to the pump, and see if anything changes. If it doesn't, the pump's not working.

[Paul Franklin]

I'll add my .02.

Your circulator is on the return side, so one would normally suspect an air lock, especially with one zone (sort of) working.

If I understand you, you:

1. Made sure makeup feed valve was full open.

1. Closed the shutoff on the return line of one of the zones.

2. Opened the drain valve on the inlet side of the circulator. This allows water to flow from the makeup feed, through the backflow preventor, through one of the zones, and out the drain valve. Flow was good and strong.

1. You repeated this for the other zone.

If this is what you did, you pressure purged the system properly, and should not have significant air in the loops.

If you are then still not getting circulation it is most likely the circulator.

But you can try another thing first.

I don't see a boiler drain valve in the picture, but I assume there is one there. Turn off the burner and let things cool a bit. Close the valve on the outlet side of the boiler. Repeat your purge but use the boiler drain valve instead of the one up on the inlet side of the circ. This will force water to flow through through the circulator and the boiler.

If you still get a solid, forceful flow (not just the boiler draining, then it really is most likely the circulator.

Shut it down, close all the valves, and drain the boiler down below the point where the circ is plumbed in. Remove the circ and bench test it.

HTH,

Paul

[Diezmon]

Yep, that's what we did for both zones.

We did try one more thing to try to rule out air and/or a frozen line: We ran hot water through each zone, using the utility sink as our hot water source. I won't bore you with details of how we did it( unless anyone's interested ), but all baseboards are working properly, nice and hot. This also allowed me to verify where the piping goes in the first floor where everything is embedded in concrete :)

I'm now convinced it's the pump, and picked a new one up today. Once I get the old one off, and prove that it's fried, I'll install the new one :)

Thanks everyone for the prompt responses!

Tim

[Stormin Mormon]

Some pumps, you can look in between the pump and the motor, and see if the coupler is spinning around.