TLDR
OK, this is not so dozy a question - and the background is below for people who want to know why I am asking this, but bottom line:
What is the technical reason for anti-cycling lockouts? Does constant firing use too much gas, wear something out - what?
Put it another way: If there was no such thing as an anti-cycling lockout, what would be the detrimental result?
[Note: On my Vaillant, even during pump run-on, at the start of the next fire after anti-cycling lockout is complete, the boiler still turns the (running pump) off and back on again, so that tells me that Vaillant aren't concerned about the extra energy required for initial pump spin to speed - if they keep on turning a spinning pump off and back on again - for no apparent reason.. so if anti-cycling is a fuel efficiency thing, why the pump shenanigans?}
Background
I have a Vaillant Ecotec combi driving DHW, an upstairs radiator circuit and a downstairs 4 zone UFH (connected to a stat/actuator controlled manifold).
The Urban Plumber did a video about how you should be able to remove the actuators and stats on the manifold and just run all zones with a low temp (say, 30 - 40C flow).
Thinking about it, it kind of makes technical sense, because heat will only transfer from a hotter area to a cooler one. For example: if the floor surface temp is 22C and the air temp in the room above is 24C, I figure that not much heat is going to transfer out of the UFH and the temp at return, won't be much different from the flow temp, unless/until the room air temp drops.
Now, I was thinking about running this low flow temp 24/7, by setting the flow to be 38C (only because any lower, and the boiler doesn't seem to fire at all). I, of course, will have to tune this as I experiment, because the flow still needs to be high enough for upstairs rads BUT I figure, over time, as the entire fabric of the house settles at around 20C 24/7, the upstairs rads can just bumble along at low temps as well.
I increased pump over-run (D1) to 11 and and max burner anti-cycling to 10 (as well as D17 to 1=Return - which should be correct in theory for low temp UFH). Anyhow, this is an experiment which I'll be tuning as I go along.
The one issue I have currently, is that after about 45 secs of firing, we hit a flow of 44C and the thing stops firing and goes into anti-cycling lockout, and so I think I need to get on top of this before I start tweaking other parameters.
OK, this is not so dozy a question - and the background is below for people who want to know why I am asking this, but bottom line:
What is the technical reason for anti-cycling lockouts? Does constant firing use too much gas, wear something out - what?
Put it another way: If there was no such thing as an anti-cycling lockout, what would be the detrimental result?
[Note: On my Vaillant, even during pump run-on, at the start of the next fire after anti-cycling lockout is complete, the boiler still turns the (running pump) off and back on again, so that tells me that Vaillant aren't concerned about the extra energy required for initial pump spin to speed - if they keep on turning a spinning pump off and back on again - for no apparent reason.. so if anti-cycling is a fuel efficiency thing, why the pump shenanigans?}
Background
I have a Vaillant Ecotec combi driving DHW, an upstairs radiator circuit and a downstairs 4 zone UFH (connected to a stat/actuator controlled manifold).
The Urban Plumber did a video about how you should be able to remove the actuators and stats on the manifold and just run all zones with a low temp (say, 30 - 40C flow).
Thinking about it, it kind of makes technical sense, because heat will only transfer from a hotter area to a cooler one. For example: if the floor surface temp is 22C and the air temp in the room above is 24C, I figure that not much heat is going to transfer out of the UFH and the temp at return, won't be much different from the flow temp, unless/until the room air temp drops.
Now, I was thinking about running this low flow temp 24/7, by setting the flow to be 38C (only because any lower, and the boiler doesn't seem to fire at all). I, of course, will have to tune this as I experiment, because the flow still needs to be high enough for upstairs rads BUT I figure, over time, as the entire fabric of the house settles at around 20C 24/7, the upstairs rads can just bumble along at low temps as well.
I increased pump over-run (D1) to 11 and and max burner anti-cycling to 10 (as well as D17 to 1=Return - which should be correct in theory for low temp UFH). Anyhow, this is an experiment which I'll be tuning as I go along.
The one issue I have currently, is that after about 45 secs of firing, we hit a flow of 44C and the thing stops firing and goes into anti-cycling lockout, and so I think I need to get on top of this before I start tweaking other parameters.
