AquaSmart pump delay function and zone controls

swvawethead

The new Buderus GC144/4 is up and running with a Taco 4 zone panel and three Taco 0015 circulators and indirect held off until the shock of this installation wears off. Basic functions seem to be working fine and pipes are full. Boiler and circulators trigger on/off, etc. and no funny noises, so I am down to getting thoroughly acquainted with the AquaSmart's features.

After reading the additional settings available beyond the factory defaults I am confused about the pump on/off delays.
I may end up answering my own question while writing up these questions.

1. If the installer used a four zone Taco controller, how does the pump on/off delay work with this?
For example, one of the zones calls for heat and Aquasmart delays signalling the pump for the set time delay I suppose the zone/pump that called for heat will run when Aquasmart delay is released? But The Taco zone controller is just a single piece that receives the on/off signal from the AquaSmart and the Taco manages the zones.

2. If a second or third zone calls for heat is the AquaSmart pump on/off delay is still simply interacting with the zone control as a whole? So while a zone is already heating how does the call for additional zones affect the on/off delay feature in the AquaSmart? I am cofused about this detail in how the AquaSmart will control the on/off delays for multiple pumps when a zone controller is used. Or is the delay bypassed if a zone is already in operation and additional call for heat in other zones will trigger on with no delay.

3. To add to my confusion, if there are multiple zones, how does the delayed off feature work with a zone controller? If a zone demand is met and a delay off is set in the AquaSmart, I have no idea this works with a zone control board.

4. Or is the extra feature for circulator on/off delay designed to work only with the AquaSmart controlling individual relays to each circulators instead of via a zone control? (For some reason this seems to make more sense.)

I did manage to understand the high and low limits and the high and low differential settings.

Thank you!

Robert O'Brien

It only controls the C1 terminal.

Paul48

Some options will not be useful to you. You should have all the documentation explaining each option. To the boiler, the ZVC is just a set of contacts, just like a thermostat. There's no communication back and forth. It is not that sophisticated.

swvawethead

Update: Just spent time with AquaSmart tech support person who was very helpful. Unfortunately the on/off delay feature is not going to work with my system with the Taco 4 zone controller and with three pumping away circulators and no indirect hotwater tank.
I vaguely get the idea this feature may work with a single circulator with multiple zone valves.
He also mentioned the on/off delay with a indirect tank setup but I didn't pursue more detail.

He pointed out the AquaSmart packaged with the GC144/4 is pre-programmed at the factory following Bosch/Buderus parameters including the high/low limits and high/low differentials.
I am afraid after I asked the installation tech about the high low limits the settings may have been changed to 160/180 but not sure about the differentials.
I think the factory setting for the high was 191 and low may have been 140.
I would like to set it back to the factory default after the Beckett tech suggested it will be best to let it do its thing for the time being.
I sent a note to Bosch to get the factory default numbers but if anyone knows I would appreciate the info.

swvawethead

I also just learned - from browsing the forum - starting with the GC144 Bosch implemented controls for maintaining boiler standby water temp with AquaSmart low limit and differential controls and the low limit settings can be turned off although I am not sure why I would do that on my otherwise normally operating system.

Paul48

Read the AquaSmart literature on how it works, and what it's for. Don't DO anything, until you fully understand Everything.

swvawethead

I read the AquaSmart manual back and forth then called Beckett mainly about the on/off delay which I cannot make use of. Then I learned maybe the factory default high/low limit (and differentials) are best left alone but I do not know what they were set at. Probably good to have that info anyway as a reference. This info is nowhere to be found and I am waiting for a reply from Bosch tech support.

swvawethead

Paul48 - just talked to a Bosch tech. He suggested I may not need the low limit controls and can turn that off. He said in our installation cold starting the boiler should not pose any issues including condensation and the boiler's ability to heat the water up to temperature. He said the low limit feature will be useful when the indirect tank is installed. The high limit and differential he suggested starting at 180/10 and monitor the operation for tweaking the differential if necessary. (I think the larger differential may somewhat help reduce gas consumption.)
He also suggested the installation tech usually knows what's best for a given system.
And it may turn out he turned off the low limit feature.