Wirsbo valve setting ?
Hi all, Im having some difficulty with one of my wirsbo valves in my hydronic/radiant system. I have 7 valves with MVA (actuators) on em mounted on a wirsbo manifold. This is on the return side. On the supply side, I have a wirsbo manifold with valves (or at least I assume they're valves) and balancing caps. The lines are uneven.. longest is about 500ft (garage), shortest is about 70ft (bathroom). Hence the balancing act on the supply manifold. The MVA's have their own t-stats, and all end-switch a relay controlling a coupla circ pumps. Today, I picked up an infrared thermo gun to check my return temps etc. I happened upon something odd. My garage was calling for heat, the valve was indicating open, circ pumps going, but the pipes were cold. The whole manifold was cold. I waited for a while, and no change. Then, a different zone opened up.. and both that zone and the garage lines got hot ! Im wondering if the MVA isnt lifting its rod high enough ? It does go in and out as I cycle the circuit (took it off and put finger on rod). Then I wondered if Ive actually set my valve bodies at the right height inside the manifold ? This would affect the height of the valve 'pin'. What is the proper height to set a valve body inside a wirsbo manifold ? [edit added this] And, if i can add some life to this valve (if its not lifting enough).. do I screw the body 'down' (but thats also closing the valve manually, isnt it ?).. or 'up (but that makes the rod itself higher in relation to the MVA outside threads). Ugh.. [/edit] I went out into the garage, and its only 1 deg below its set temp and still calling for heat. It looks like its gonna get some as long as some other zone calls.. but I cant leave it like this.. eventually if I have to open the garage door i might end up freezing my paints etc. (I keep the garage at ~5c.. just a few above freezing..) Thanks for info, (ps.. been poking around other corners of this diy site.. just so great .. wish Ida found it years ago.. too bad not much demand for info from my line of work.. lol (telcom mainline worker) ... anyhow.. cheers to the readers and repliers all !) Dave, is there a model # on the valves that I can google and see if I can scare up the manual? Even if it's set up wrong though, I can't understand why it seems you get no flow until another zone opens... You need to have both pumps running, the boiler and the radiant, if I recall correctly? but your air handler only runs it's own pump, correct? I guess your boiler pump is wired to the aquastat on the boiler, and the radiant pump is running off a zone control panel? and the endswitch on the zone control panel fires the TT terminals on the boiler aquastat? edit- never mind, I just remembered you run the boiler fixed temp... and the boiler pump is running off the same relay as the radiant pump... well... I didn't remember, I looked at your diagram... Thx for the reply, Trooper. From the info I have the model of the manifold/valve assembly is wirsbo part A2553220. I have 2 sets of these on the supply and return side. The motorized actuators are on the return side. I was reading over my manual for them again, and its seeming like it doesnt really matter where you set the valve inside the body.. fully down is closed, 2 turns up is fully open. When you screw the MVA onto them, the indicator onboard the MVA shows you where to 'match' the closed position to meet the pin. I bet thats another MVA shot. Gettin tired of replacing these things.. Uhoh.. this is gettin weird on me now.. As before, if any other zone was open, the garage zone would be getting nice heat (measured at ~100f with my new IR meter). But as soon as that 'other' zone closed off, the line cools off. In fact, the whole return manifold, the line from the return manifold to the mixer (cold side), and the mixer output to the supply manifold would go cold. It would literally drop from 100f to 68f in about 20 seconds. I took the MVA off, ensured both valves were manually wide open for that zone, and manually closed off all the other zones (on the supply side). That zone is still calling, so via the end switch of the MVA hanging there.. the circ pumps are still running. I get 150f on the supply line fairly close to the mixer, 150f on the return line at the boiler. But the whole loop thru the mixer from supply and return is stone cold. The fact that the manifolds etc cool down so fast indicates the loop circulator is pumping, Id think. The only thing I can think of, is that the pressure drop of that long garage loop (~500ft if i recall) is somehow causing the mixer to stick to fully cold mix. Once some other zone opens up, there would be more pressure on the cold side of the mixer allowing it to operate properly. Is this possible ??? The mixer is a Honeywell AM Series Again, thx for any info. I'm gonna re-post your system diagram so's I can look at it while thinking about this... wierd! Dave, are there 'flow meters' on the supply manifold with the adjusters on them? If so, can you _see_ that there is flow in the loop? Here's an idea that I haven't finished formulating yet, but it has to do with the boiler pump possibly 'overpowering' the radiant pump... and I'm not even sure this makes any sense, but I'm gonna throw it out for discussion... What if, with only the garage zone open, it's working against a fairly high head, and not really pumping all that much water... and the boiler pump is presenting a lower pressure at it's suction side than the radiant pump is capable of overcoming? You might end up with a situation where the boiler pump is 'robbing' the radiant of all the heated water... and the water in the radiant loop just goes round n round... Then, when another loop opens, the radiant pump moves a bit on it's 'curve' and begins to pump more water... and now there is enough on the suction side to overcome the 'pull' of the boiler pump and divert some of the heated water to the loops? I know it's weird, but it's the only thing I can think of... Honestly, I would consider re-piping that setup ... you've got two pumps competing for flow there. Dave, do this and you can wipe the egg off yer face! But if you did this, you would need to do some control changes so that the boiler pump ran with the air handler pump... just another idea to toss around... might be all wrong. What got me thinking about this was the question in me haid: What happens when the radiant calls for heat, and then the air handler calls at the same time? But, you wanted P/S , right? Yep, I can see how that edit works. Might have been a good plan from the beginning. My pipefitter followed what the engineer at the supply house said.. plus his own history/etc. Not that it was right, of course. It would probably be beyond me to start threading lengths etc for a refit.. using stock pipes would probably involve a larger rebuild. Im hoping that would be a last resort (am i in denial ? lol) Using that properly spaced gap for supply/return spacing seems to be a standard. But.. that would solve it if its the pumps are battling for flow in the high-head situ, as you said. If its the mixer not dealing with the high-head.. low flow ?.. then it wouldnt. I think the radiant circulator is flowing ok, because of the speed that the pipes go cold. Id have to go down and retest it with a timer.. but its certainly not just ambient cooling. The room is warm, and the pipes go from 'hot' (100f), to actually 'cold'.. very quick. If the boiler pump was 'winning' the flow game, Id think some hot would be coming up the return line (below the boiler pump), and up thru the mixer's cold side, no ?? Appreciate your interest in this non-standard situation. ps: how are you editing those drawings so nice and quick anyhow, trooper ? lol.. almost like I gave you the actual Smartdraw file ! nice work. If the boiler pump was 'winning' the flow game, Id think some hot would be coming up the return line (below the boiler pump), and up thru the mixer's cold side, no ?? What if it were an even race? a tie? Everything the boiler pump pulled out of the boiler would go back in... and vice versa with the radiant pump... no flow in on the hot supply side of the mix valve, just re-circ on the cold side. What bothers me about this though is that if the mix valve is really cold, then the valve should have the cold side almost all the way closed, and the hot side almost all the way open... so how could my theory be true? I dunno... but I got nuttin' else! OK, I know, but I gotta ask: You don't accidentally have that bypass valve that's marked N.C. open, do you? ps: how are you editing those drawings Photo-editing program... liberal use of the 'selection','clone',and 'erase' tools... basically move stuff around with the selection tool, then clean up with the erase tool, then reconnect stuff with the clone tool. Originally Posted by NJ Trooper You don't accidentally have that bypass valve that's marked N.C. open, do you? The valve is seated, and that loop only seems to change temperature by conduction from the nearby pipes. So, seems like the valve is closed properly. (thats actually part of my poor-mans a/c.. I bypass the slab pump, close off the boiler pump (both powered off of course), and let the air handler pump push liquid thru the manually opened zones. It chills the air, but not by much...) Im tryin to re-find a website reference for that zone valve that mentioned some 'certified down to 0.5 flow rate'.. 0.5 I didnt note.. 0.5 gpm ? If Im getting less than 0.5 of whatever it was for flow.. maybe the zone valve defaults to cold ? Too bad I dont have a flow meter in there somewhere. [edit: just found it its 0.5 gpm 'min flow rate' for a Honeywell AM series mixer. ] Is there a way to calculate the theoretical flow rate based on the pump and length of line ? You could probably do a reasonably close estimate if you knew the length of the tubing, and had the specs on it for head/100ft... then estimate the head from the other piping/elbows,etc... and the pump curve... I don't recommend this as even a semi-permanent fix, because you wouldn't want to throttle the suction side of a pump, but... as a test... what if you choke down the valve on the suction side of the boiler pump? what happens? Originally Posted by DaveC72 Im tryin to re-find a website reference for that {{mixer}} that mentioned some 'certified down to 0.5 flow rate'.. 0.5 I didnt note.. 0.5 gpm ? If Im getting less than 0.5 of whatever it was for flow.. maybe the {{ mixer }}defaults to cold ? Change zone valve to mixer in my above post. I tried closing the boiler loop circ pump, and the garage loop did go hot. By pipe feel, it seemed like the slab circ was pumping thru the boiler now. I didnt check to see if the mixer was now actually working, or just sending fully hot. That shutoff was leaking at the stem.. took me a while to find a position to seal it again (great.. those cast iron fitting come apart soo easy... why we used gate valves there I dunno..) The slab pump is a Grundfos UPS 15-42, but sadly, its already at max speed. The boiler pump is a Taco 007, so no adjustment there. If its really the pumps battling for flow, wouldnt this have been happening from the get-go ? I dont remember the circ's ever running as much as they do now. I tried closing the boiler loop circ pump I didn't mean to close it all the way... that's bad for the pump, and if it's closed now, open it! What I had in mind was closing it slowly whilst feeling at the pipes in an effort to determine WTH is going on... kind of an experiment to support or disprove my theory. I _think_ it worked to do that? If its really the pumps battling for flow, wouldnt this have been happening from the get-go ? I would think so... but maybe ya just never noticed it? Let's re-cap a bit, and let me ask a couple more questions... TRUE/FALSE The garage loop will never heat up if it's the only loop calling. TRUE/FALSE The garage loop WILL heat up if ANY other zone opens. IOW, this phenom is not associated with the garage and only ONE other particular loop? And all the other loops are much shorter than the garage loop? leaking at the stem.. took me a while to find a position to seal it again Just below the handle, there should be a 'gland nut' which compresses the 'packing' around the valve stem. You should be able to tweak that gland nut a little tighter and stop the leak. I've found that for some odd reason, if you open the valve all the way to the stop, it will tend to leak at the stem more readily. What I do is open them all the way, then about a quarter turn closed. I think this allows the stem to 'float' in the body and move with heating/cooling, but not sure... just something I noticed a long time ago. Originally Posted by NJ Trooper I didn't mean to close it all the way... that's bad for the pump, and if it's closed now, open it! With my hand on the pipe near the slab circ, I closed the boiler pump line off, then cracked it open a wee bit.. I didnt want to run it dry either The valve was leaking a steady drip here, so i opened it up more till it slowed down (valve was maybe 3/4 closed ?).. seemed the slab line continued to warm up. The valve is back to open now. TRUE/FALSE The garage loop will never heat up if it's the only loop calling. True TRUE/FALSE The garage loop WILL heat up if ANY other zone opens. True IOW, this phenom is not associated with the garage and only ONE other particular loop? And all the other loops are much shorter than the garage loop? I witnessed this with zones 1,2 and 6. (all bedrooms, lengths maybe 150ft ?). zone 5 is garage. zones 3 (~200ft) ,4 (100?) and 7(70ft) operate on a shared tstat (for now). Ill go force that combo zone and see what happens tonight. Just below the handle, there should be a 'gland nut' which compresses the 'packing' around the valve stem. Last time I did that on one of those gate valves, the nut broke.. it may have been split already from thermal cycling.. not sure.. it just kind of peeled off as i tightened it.. lol The existing valve was such that the nut was trapped, but you could pull the whole valve out of the body.. but the replacement from the same store didnt have the exact same insert thread design.. had to take the valve off. Ill give it a wee turn tho Oh geez.. this is gonna get odd now.. So I go to the util room.. for some reason I decide to first adjust the outlet temp using my new IR thermogun. Might not be related, and I did adjust it up and down before today.. anyhow, I set it for outlet temp from the mixer at 100f. Zones 1 and 6 were running at the time. Also of note, earlier today I had tried setting the speed of the Grundfos down to 2 and 1, then back up to 3. Just in case it was labeled wrong etc. Now, the other zones go off, so I manually start the garage zone. Now I have circulation. But its odd.. Im getting cold out of the slab, to the connection point of mixer cold side line.. Ive got hot coming in from the boiler pump output line (line between the boiler pump and the mixer cold-in/slab out) now (that line has never been 'hot' that Ive noticed before.) and it appears to be mixing there and going up to the mixer 'cold line' (pipe warm). The mixer out was showing 100f for the brief chance I got to measure it before another zone opened. Once that other zone opened (i think it was 2)(Im still holding the garage zone open manually), the cold side pipe up to the mixer cooled down alot. Im not sure whats up for sure.. did the gate valve stick in the stream ? It felt ok closing.. Did I accidentally find some magic point in the mixer where it can deal with the low flow ? Not likely, but possible depending on design (??). Could the Grundfos pump have been actually on 2, while indicating 3.. or otherwise electrically running in '2' ? Possible.. Are there sometimes boiler demons that screw around with your brain like this ??
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