DoItYourself.com Community Forums > Heating, Cooling, Air Conditioning, Ventilation and T-Stat Controls > Boilers - Home Heating Steam and Hot Water Systems

TACO outdoor reset when using a priority DHW zone

Thread Tools

Search this Thread

10-20-14, 09:21 AM

wvhughes

Member

Thread Starter

Join Date: Oct 2014

Location: USA

Posts: 1

Upvotes: 0

Received 0 Upvotes on 0 Posts

TACO outdoor reset when using a priority DHW zone

I have a ZVC404-EXP zone control set up with a priority zone for DHW (zone valve, not circulator). I also have a PC700 outside reset. It seemed to get stuck in hot water mode because the PC700 set the boiler too close to the DHW setpoint. I am guessing I should switch to a PC702 that will set the boiler to 180 when in priority mode. Is this correct or is there another option? What do I do with the stage 1 and stage 2 outputs of the PC702? Can the DHW demand wires just be paralleled with the zone valve motor for the priority zone?

Upvote

10-20-14, 02:05 PM

lawrosa

Super Moderator

Join Date: Dec 2010

Location: Galivants Ferry SC USA

Posts: 15,984

Upvotes: 27

Received 79 Upvotes on 71 Posts

Hello and welcome to the forums..

For reference...PC 700

http://s3.supplyhouse.com/manuals/13..._PROD_FILE.pdf

Can you tell us the make and model of the boiler please? Also make and model indirect?

Once we get that info we can work on getting an answer to your issue.

Upvote

10-20-14, 05:04 PM

NJT

Member

Join Date: Oct 2006

Location: USA

Posts: 19,710

Upvotes: 0

Received 8 Upvotes on 6 Posts

I don't think you want the 702, that one is for MULTI-STAGE boilers which you don't have.

Upvote

10-20-14, 05:16 PM

NJT

Member

Join Date: Oct 2006

Location: USA

Posts: 19,710

Upvotes: 0

Received 8 Upvotes on 6 Posts

Quote:

It seemed to get stuck in hot water mode because the PC700 set the boiler too close to the DHW setpoint.

I'm not sure what you mean by this?

You mean that the boiler is operating at the ODR setpoint even on a call from the DHW and doesn't get hot enough to bring the DHW tank up to temperature?

It shouldn't do that. It should fire to high limit on a call from DHW.

Do you have the dipswitch "RESET - NORMAL" pushed over to RESET?

Upvote

Thread Tools

Search this Thread

Show Printable Version

Email this Page

Boilers - Home Heating Steam and Hot Water Systems
Which way should water flow through a 3way Taco zone valve?

B

blambmn on Oct 19, 2014

I have an existing oil filed hot water boiler with 4 zone valves. Am now adding an outside wood boiler and will use a flat plate heat exchanger to connect the outside boiler to the existing in house boiler. I intend to use the one existing circulator pump to run water through the heat exchange at all times (the pump will remain on at all times. So what I need to do is use a 3 way zone valve to allow water to run from the boiler, out towards the heat register, but when no heat is required it will simply redirect the water to the inflow of the oil boiler, thus bypassing the other zone thermostats. But I'm confused. The Taco 3 way zone valve shows the water is to go in the UNIT and BYPASS openings, and out the MAIN. Can I use this 3 way on the beginning of my bypass (where hot water leaves the boiler) or do I need to put it on the end of my bypass (where hot water comes from the existing zone valves and reenters the furnace? And if I do use it on the inlet, does MAIN connect to the boiler, BYPASS connect to the new bypass, and UNIT connect to the existing zone valves?Read More
Boilers - Home Heating Steam and Hot Water Systems
Split single zone house - DIY

R

rschwarz_jr on Oct 12, 2014

I have a decent sized two story house that is all one heating zone. I really want to improve the comfort of certain areas and if there is some energy savings that would be great. My system is baseboard hot water and has a single thermostat in the dining room that controls the whole house. All of the piping to and from the baseboard radiators was replaced a few years ago with pex (previous owners). There are 4 loops, one to each area I want to zone but they don't split off all together in one spot like a manifold. There is a larger copper pipe that crosses the whole basement and there are four Ts. At each T it changes to pex and has a shutoff valve and is the beginning of a loop. It's like a manifold that is stretched across the whole basement. On the other side of the basement its the opposite. A large copper pipe with four Ts and all of the returns. It seems like it's perfect for adding zone valves except the valves would be spread across the basement instead of all in one nice neat location. I have an oil fired boiler that also does domestic hot water. Controlled by a hydrostat 3150. Here are my questions: This seems strait forward, is this a good DIY project? Does it matter that the zone valves would be in different locations across the basement? I was looking at a Taco ZVC406-4, good choice? What's the best zone valve for the job, Taco, Honeywell? Does it matter if the valves are on the supply side or the return? Return would be easier in my situation. Having never worked with pex myself what the best way to attach the zone valves inline with the pex? And finally is there anything I'm not thinking of?Read More

Ask a Question