Weil Mclain GV4 series 2 Condensate Question

[Fletch1]

Locking out again. Boiler will work for sometimes hours or even a a couple of days then locks out, won't restart, not even after several manual (power off then on) tries. If it don't light the 1 st time around it is supposed to automatic retry 2ice more. But that's not whats happening, it's locking out without retrying. I've never seen that before. Ive gone over all the voltages etc, blower, I checked the pressure switch and it's OK, but just to be sure I replaced it with a new one. Igniter is also new. I think the only thing left is the logic board itself, or possibly the overtemp switch that's mounted directly on the boiler cast iron surface. So after fiddling with it for a while it finally stated working. Been 2 hours now and still ok..

 

[Dana]

The vinyl clad wood low-Es are probably U-0.30-0.32 ish. The Starmark Okna might be 0.25 if it's their double paned "HeatShield" glazing. Assume the older l0w-E double hungs are U0.35 .

With trussed roof and cross-installed double layers of R19-R22, use U0.020 for the ceiling U-factor -it'll be close enough.

A 2x4 R13 cedar shingled wall stackup runs about U0.09 if the structural sheathing is plywood or 1x planking, about U0.083 if the sheathing is 3/4" asphalted fiberboard (which it probably is.)

If it's fin-tube baseboard you don't have enough thermal mass in a 22' section to help out much.

Runtal makes variety of baseboard rads of different heights, and the output per foot varies quit a bit. The UF-2 runs about 600 BTU/ft-hr @ 180F, which is about the same as typical fin-tube. UF-3 runs 770 BTU/ft-hr, and UF-4 runs about 9305 BTU/ft-hr, or about 1.5x the output of typical fin tube. The thermal mass isn't significantly more than fin tube though.

 

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[Fletch1]

Yes asphalted fiberboard. yes UF2. Don't want to speak to soon ,but the lockouts seem to have been an "iffy"/ bad ground. Been good all night and all day. Time will tell.

 

[Fletch1]

Dana, I still have this WM GV4 Series 2 boiler. I have not changed anything since the last post in 2016. In 2017 we went through the heating season without an issue. Now I have a question I hope you can provide advice to. No one lives in the downstairs zone anymore. So I could just heat the upstairs living area zone and not use any other zones. Doing so would reduce the time to bring water warm up to non condensing temp because then only the water in the one zone is heated. The downside is it will short cycle.

Or I could simply manually open up the downstairs zone and a spare bedroom zone so that when the living area calls for heat those other zone will also heat pretty much like all one zone. (I'm doing that now as an experiment). My cycle time now is a consistent 4 minutes 30 seconds which I know is not long but it is at least a minute more than it was. To me, the downside is it will take longer to get the water to a non-condensing temp. Nither of these are a great work around but of the 2 which is the better option?

 

[Dana]

Rather than make me re-read the whole thread, give me the DOE BTU output numbers of the boiler, and the amount of radiation on each zone.

A 270 second burn cycle is shorter than ideal, but not the same kind of efficiency disaster 100 second burn times would be.

 

[Fletch1]

Rather than make me re-read the whole thread, give me the DOE BTU output numbers of the boiler, and the amount of radiation on each zone.

A 270 second burn cycle is shorter than ideal, but not the same kind of efficiency disaster 100 second burn times would be.

DOE 92 MBH 59" fin tube in Zone 1, 20' zone 2, 12' zone 3, 12' zone 4, 12' zone 5, these zones are 3/4 copper. Zone 6 is Runtal baseboard 6' using 1/2 pex.

I now have 3 zone valves manually open. downstairs family room , upstairs Bedroom, and the 5 Runtal UF-2 upstairs bathroom . All seem to flow OK when the circulator on Zone 1 turns. When it's off there is a gravity reverse flow through the open zone valves. I think I'm OK with that.

I also have a indirect water heater HTP superstore 35 gal.

 

[Dana]

Is that 59 inches (not quite 5') or 59 FEET of fin tube for zone 1?

At 180F out, 170F average water temp the fin tube only emits about 500 BTU/hr per running foot.

Runtal comes in a number of different heights, so without knowing which version there's no way to put a realistic number on it. Scanning the thread it's UF-2(?) which is good for about 600 BTU/foot.

If I understand it correctly , by manually keeping some zone valves open you have it set up that zone 1, 2, 3, and 5 (or is it zone 6) are all operating off the zone 1 thermostat? In one sentence zone 5 is described as 12' of fin tube, then there's a reference to zone 5 being Runtal, which is making it a bit confusing...

Which zones are the downstairs zone & bedroom that you're thinking of turning off?

 

[Fletch1]

Upstairs' 59 feet of fin tube for the living area zone . 12 feet in each of the 2 bedrooms, each on their own zone. 6 feet Runtal UF-2 Bathroom

The 3rd bedroom is part of the living area zone so the 59 feet includes it..

Downstairs family room 20 feet fin tube.

Currently I've manually opened the taco zone valves for the family room, one bedroom , and the Runtal bath room. All working off the living area thermostat. Water seems to flow ok when the living area thermostat calls for heat. However when the circulator stops there is a reverse flow through the open zone valves. Here is a photo link so you can see actual zone locations on the manifold. I will number them one through 6 from left to right.

#1 upstairs BR, #2 MBR #3 Living area #4 Family Rm, #5 Downstairs Bath currently not used, #6 upstairs Runtal bathroom.

https://www.screencast.com/t/rSfHQFri

 

[Dana]

This is getting lost in the semantics & extraneous details or something. Nobody adds multiple numbers left to right- Make two ordered lists, and do it vertically to make adding the columns of numbers easier. One list will be the zone(s) that you want to keep using, the other list is those you want to turn off. eg:

Active zones:

1: 59' of fin tube living space

2: 12' of fin tube bedroom

3: 5' of UF2 bathroom

...etc (It doesn't really matter how you number or name them, but it'll probably be easier for you to keep track by using the names and actual zone numbers on the zone controller.)

The a corresponding list of zones & radiation you want to leave off.

 

[Fletch1]

I'm sorry I'm not expressing this as I should. I will take some time to rethink this. Thanks for trying to help. i will get back to you soon.

 

[Fletch1]

WM GV4 Series 2 DOE 92 MBH

Active Zones Inactive

1: 59' of fin tube living space 6: No emitters installed

2: 12' of fin tube bedroom

3: 12' of fin tube bedroom

4: 6" Runtal UF-2

5: 20' of fin tube downstairs family room


A: Currently zones 2, 4, and 5, are all manually opened and operating off the zone 1 thermostat. The downside is during cold starts there is a greater quantity of water to heat to 130F or higher to prevent heat exchanger condensation.

B: This boiler is known for thermostatic valve failures and I don't know if mine is working. However I could use just zone 1 and 4 and that would reduce the quantity of water and time heating to 130F . The downside here is shorter cycle times. Zone 2 would only be used on the coldest of nights if at all.

Which is preferable A or B?

How can I tell if the thermostatic valve is functioning?

Would a scope up the flue to the heat exchanger tell much about the condition?

Thank You

 

[Dana]

So to be sure I've got it, your plan B is to run just the 59' of fin tube and the 6' (not 6") of UF-2, and stop running the combined 24' of bedroom fin tube and the 20' of baseboard downstairs(?).

You are currently running everything except the 12' of zone 3 baseboard off the zone 1 thermostat, having manually opened zones the valves for zones 2,4 & 5, and getting ~270 seconds of burn time per burn cycle.

If your high-limit temp is 190F for an average water temp of 180F the radiation is emitting about 59,000 BTU/hr. With the boiler's DOE output of 92,000 BTU/hr that's 33,000 BTU/hr of excess heat going into the system . If you cut back to plan B with 59' of fin-tube + 6' of UF-2 it will be emitting about 40,000 BTU/hr. and ~52,000 BTU/hr of excess. That's going to reduce your burn cycle times to 270 s x 33K/52k= 171 seconds- less than three minutes.

If it's only 4-5 cycles/hr it's not going to shorten the lifespan of the boiler, but the as-used efficiency will be lower. Even at the lower efficeincy the fuel use will go down if your keeping most of the house cooler, since the heat loss from the house will be lees.

You can probably improve upon that with a retrofit heat purging economizer control such as the Intellicon HW+ or Hydrostat 3250 programmed to heat purge to 130F before firing the boiler, and raising the high limit to the maximum.

 

[Fletch1]

Hi limit currently set 180.

Running 2, 4, 5, off the zone 1 thermostat is not working out. Zone 5 will not flow with zone 4. Shutting down zone 5 allows zone 4 to flow, but it flows in reverse. Crazy I know, but I'm sure of it. Must have something to do with the manifold locations of each zone tee. Plan C , will try running 2, 3, 4, off the zone 1 thermostat. That makes 89 feet of baseboard.

I will certainly look into Intellicon HW+ or Hydrostat 3250 . Thanks for your help.

 

[Dana]

You can probably fix the zone flow issues with zone balancers or even a few ball valves for throttling back flow on the lower-head zones that are hogging all of the flow.

 

[Fletch1]

Thanks Dana, there are ball valves on each zone, mounted above the zone valves on returns. Interesting article, I will be sure to give it good read.

 

[Dana]

Thanks Dana, there are ball valves on each zone, mounted above the zone valves on returns. Interesting article, I will be sure to give it good read.

With the ball valves you can turn down the flow on some branches to force flow in to others. The branches with the most "equivalent length" of plumbing + baseboard have higher pumping head/lower flow that those with shorter plumbing lengths. So it's really the shortest loops that are hogging the flow. Every ell & tee along the path adds some "equivalent length" to the numbers, so it's not necessarily going to be the loops with the least straight-pipe runs.

Running a ball valve partly closed will put some wear on the valve, but I suspect the gpm here would still be pretty low, low enough that it's not going to wear it out quickly, and can probably run for decades without sufficient wear to keep it from sealing completely when fully closed. Globe valves and balancers are designed to restrict flow without much wear, but simple cheap ball valves can usually "do the job".

 

[Fletch1]

New issue. When the living room zone stops calling for heat the 2nd BR zone valve that is manually open still thinks there is a call for heat and keeps the boiler running. Even if I turn off all the thermostats off. Is the 2nd BR zone valve head bad?

 

[Dana]

Analyze the system control schematic. It's unlikely to be a faulty zone valve. Does it all shut down properly if the 2nd BR valve isn't manually opened? What is controlling the pump?

 

[Fletch1]

When 2nd BR zone valve is in automatic mode it works normally and everything works and shuts down normally. I don't think there is a system control schematic.

When I say the boiler is running I mean the boiler keeps going through complete heating cycles.

 

[Dana]

I assume that means the boiler is firing and reaching the high limit, but is the pump running as well, behaving as if there was a constant call for heat from a thermostat?

If yes, does it work any differently if the zone 1 valve is manually opened, and everything is running off the second bedroom's thermostat?

Is there a zone controller operating all the valves, or are the thermostats controlling the valves directly?