Should CH pump and valves remain on all time CH is on?

[akist]

As we are heating up a house we eventually reach a required temperature on the thermostat and the boiler stops.

At that moment we want the pump to remain on so as to distribute latent heat from hot rooms into colder rooms.

But if someone has left a window open, then we do not want to distribute heat into that room while the boiler is off (stealing heat from hot rooms).

Is the S-plan configurable as to what should happen when the room thermostat reaches temp?

 

[ianmcd]

Simple answer is no

 

[Mister Banks]

There is an argument that condensing boilers and s plan systems should not be seen together. If you want control of your heating on a room by room basis then a smart control setup such as Hive or Wiser is required.

 

[dilalio]

As we are heating up a house we eventually reach a required temperature on the thermostat and the boiler stops.

At that moment we want the pump to remain on so as to distribute latent heat from hot rooms into colder rooms.

But if someone has left a window open, then we do not want to distribute heat into that room while the boiler is off (stealing heat from hot rooms).

Is the S-plan configurable as to what should happen when the room thermostat reaches temp?

That is not what pump overrun is for.

 

[old duffer]

when my heating is on, the pump runs even if the burner is not in operation.
My understanding is that if the pump is not running then no water circulates and as the temperature is rising in the primary heat exchanger beyond it's preset limit it shuts down...a safety feature perhaps! Mine also monitors return temp so when it detects sufficient drop, it ignites the burner.
Is my boiler different to every other boiler or is that what they all do?

Now the monitoring of an open window...this would have to be a sensor on the window as a thermostatic control would sense a cold room and shut down. You can't have logic that contradicts. So it would require a direct link to a TRV and the window sensor. They have been around for years but you would need it integrating and create logic in the controller and most systems don't talk to each other. You could easily create this with a single board computer and RF addressable TRV's and room thermostats, you will fins many examples of this online.

As for the design layout question
This is again a relatively simple solution but again you will have to create it yourself. The issue with this DIY will also be dictated by your current circuit design. If you have for example, a 22mm main flow/return and then each individual rad has a 15mm pipe from the main circuit, you can fit an RF TRV as you will have individual control within a circuit.

 

[Johntheo5]

Normall, a gas boiler will run/fire continuously until all zone valves or all roomstats are satisfied, the burner will then trip but the circ pump will continue to run for a few minutes based on the overrun time, to cool down the combustion chamber. If the heat demand is less than the minimum boiler output then the burner will trip at the target temp+5C, the pump will continue to run continuously, the burner will then refire after the anticycle time has elapsed, providing the flow temperature has fallen to target temperature-5C.

Not sure how it works with these smart roomstats or controllers like Evohome where the boiler can fire on/off (cycle) up to 6 times/hour, I don't know if the boiler circ pump then does a pump overrun each time but I imagine it should. Oil fired boilers generally do not do pump overruns so with Evohome and the like all the water in each rad is available to each individual room on shutdown so maybe gives better room temperature control??.

 

[ericmark]

My TRV head eQ-3 has window open detection, so if the temperature drops fast it will turn off for a set time. Not seen the option with the Energenie or Kasa, but not looked, and although it says window open, really used for door open when unloading shopping from car.

My boiler (oil) does cycle when thermostat remains on, so pump still running, as are the motorised valves. But in a gas boiler the pump and motorised valve is often integral.

With a W Plan integral in boiler we as users do not know when pump is running or what speed. As to moving heat radiator to radiator yes this would work with fan assisted radiators with laged pipes, but with non fan assisted all radiators would cool as same rate, so would not help.

The problem to my mind is with electronic TRV heads is there are no standard functions, some have twin sensors one for air one for water one for air, as said some have window open detect, some even work out when to turn on to get room warm by a set time (wiser) but to find a chart saying which do what I have failed to find.

As to motorised valves well clearly TRV electronic heads do make the TRV a motorised valve, and thermostats like EPH can work standard motorised valves independent to the running of the boiler using OpenTherm, I think one master can have nine slaves, but not actually used them.

I see Hive being sold as multi zone, so assume there is some software link. But this is the problem, one only studies software once you have the thermostat, I got Nest in error as told it worked with my TRV heads, and only found this was wrong after I had installed.

 

[old duffer]

Normall, a gas boiler will run/fire continuously until all zone valves or all roomstats are satisfied, the burner will then trip but the circ pump will continue to run for a few minutes based on the overrun time, to cool down the combustion chamber. If the heat demand is less than the minimum boiler output then the burner will trip at the target temp+5C, the pump will continue to run continuously, the burner will then refire after the anticycle time has elapsed, providing the flow temperature has fallen to target temperature-5C.

Not sure how it works with these smart roomstats or controllers like Evohome where the boiler can fire on/off (cycle) up to 6 times/hour, I don't know if the boiler circ pump then does a pump overrun each time but I imagine it should. Oil fired boilers generally do not do pump overruns so with Evohome and the like all the water in each rad is available to each individual room on shutdown so maybe gives better room temperature control??.

how do they operate when they are using flow temp rather than room temp? The pump (i assume) has to continually run in order to sense return temps. If it does not do this. how does it work?

 

[stem]

we want the pump to remain on so as to distribute latent heat from hot rooms into colder rooms.

In practice that wouldn't work effectively anyway. If some rooms were at 15 degrees and others were at 20, the temperature of the water in circulation would average out at somewhere in between; and a radiator at 17 degrees wouldn't make any noticeable or measurable increase to the temperature of a room at 15 degrees. [Most radiators have a surface temperature somewhere between 50 to 80 degrees when in operation.] So, I suspect that you would probably use more energy running the pump than any heat you may recover.