Remote control of boiler flow temperature?

[JonathanM]

As delivered it runs self modulating at setting 85 which can be adjusted. It will operate anywhere in the graph shaded area. If you set a parameter between 10 and 20 then the pump changes to hold that ∆T.

Got it now! Thanks.

 

[Lower]

I'm looking into a new regular boiler, or maybe a system boiler.

I'm a bit hopeless with tech. Is there an app, or smart controller, which lets you remotely alter the boiler flow temperature? Reason is, I might want to run the CH very cool, but be able to boost the temperature for DHW. It's a bit clunky, but I envisage turning DHW on for an hour a day and turning CH off. But, I wouldn't want to have to go into the garage and change the temperature manually every time.

Are there better ways to do this? I've mainly been looking at Worcester Bosch. They have an option for a "diverter valve" on the system boilers. Does anyone know if this lets you have the CH and DHW at different temperatures? Any other options?

Couldn't you do this by setting up your system with two circuits linked by a mixing valve in the same way as an underfloor heating setup works? You could run the boiler at the higher temp which would feed the DHW circuit and then have a the mixer valve allowing cooler water through to the central heating circuit.

 

[Madrab]

@vulcancontinental ... looking to find these vids you mention - I can only find one under your name titled -

Answering criticism of cases on current Vokera boilers​

Is that you in the vid? I'm interested to see the implementation.

Ultimately I am looking to alter existing systems with the minimum of change/expense and alterations to the systems that are currently OT/Smart enabled.

 

[vulcancontinental]

@vulcancontinental ... looking to find these vids you mention - I can only find one under your name titled -

Answering criticism of cases on current Vokera boilers​

Is that you in the vid? I'm interested to see the implementation.

Ultimately I am looking to alter existing systems with the minimum of change/expense and alterations to the systems that are currently OT/Smart enabled.

I do the videos in my own time but in our training rooms. They’re not of a quality good enough for the company so I post them in my account, vulcancontinental. A search for that or the name Vokera in the title will list them.

 

[Madrab]

I do the videos in my own time but in our training rooms. They’re not of a quality good enough for the company so I post them in my account, vulcancontinental. A search for that or the name Vokera in the title will list them.

Thanks for that, cant seem to find any re OT control etc though with your name or vokera , must be the way I am searching.

 

[JonathanM]

If TRV's close the pump will slow down rather than speed up.

'Overpumping' is the cause of narrow ∆T's.

I've always had trouble understanding flow and pressure, so I know this is going to sound stupid, and please bear with me.

But, in my head, when the TRVs start to close down, this increases the resistance of the circuit, like closing down a lockshield, and therefore the pump needs to run faster to keep the same flow rate. If someone could advise where I'm going wrong, I think I will finally get it.

 

[Madrab]

That's where an auto bypass comes in, as resistance rises the auto bypass opens allowing the required flow through the boiler to be maintained until the system shuts down, usually on over-run.

 

[Deleted member 267285]

Thanks for that, cant seem to find any re OT control etc though with your name or vokera , must be the way I am searching.

When you have searched for VC, then click the name, then videos on the tab, should end up with something like this:

 

[Lower]

I've always had trouble understanding flow and pressure, so I know this is going to sound stupid, and please bear with me.

But, in my head, when the TRVs start to close down, this increases the resistance of the circuit, like closing down a lockshield, and therefore the pump needs to run faster to keep the same flow rate. If someone could advise where I'm going wrong, I think I will finally get it.

Theoretically, the pump should maintain the same speed to achieve the same flow rate, but the power it consumes to achieve the same flow rate will go up.

 

[vulcancontinental]

Thanks for that, cant seem to find any re OT control etc though with your name or vokera , must be the way I am searching.

Search BeSMART, some we did for the company others by myself.

What specifically do you want to know?

One I did for Allen Hart but never got sent.

can't even remember what's in it.

 

[Johntheo5]

I've always had trouble understanding flow and pressure, so I know this is going to sound stupid, and please bear with me.

But, in my head, when the TRVs start to close down, this increases the resistance of the circuit, like closing down a lockshield, and therefore the pump needs to run faster to keep the same flow rate. If someone could advise where I'm going wrong, I think I will finally get it.

Maybe this will be of some help.

Radiators are designed to give their rated output at a dT of 50C between the mean radiator temperature and the required room temperature, generally assumed at 20C but you can use your own value. The mean rad temperature is the (flowtemp+the return temp)/2, so a radiator with flow/return temps of 75/65C will have a mean rad temperature of 70C and it will give its 100% rated output, meanrad temp-20, 70C-20C, 50C, so you have a 50deg rad.
A 1kw rad will then require a flowrate of 1X860/60/(75-65), 1.43LPM. The (small) room heats up and for whatever reason, ambient temperature etc, the rad now only requires to emit 0.5kw to maintain a room temp of 20C, the rad is equipped with a TRV which senses the room temperature, when the room temperature rises very slightly, the TRV will throttle the flow through its valve and through the radiator to give a return temperature of 23.8C = a "29.4deg" rad, (75+23.8)/2 - 20 and a flow of 0.14LPM, ( 0.5kw), the circ pump now only needs to circulate 0.14LPM vs 1.43LPM, the pump, depending on its operating mode can either stay at the same head in CP mode with speed reduction, or increase in head (no change in speed) CC mode or reduce head still further in PP mode with further speed reduction. The TRV will react to these different heads by simply throttling up or throttling down the valve to maintain the exact flow requirement of 0.14LPM.

 

[JonathanM]

Maybe this will be of some help.

That is very helpful. Especially explaining CP and PP, which I've never understood. Pressure and flow is like a mental block for me, and it's never going to be instinctive, but having some underpinnings to think it through like this is really helpful.

 

[old duffer]

Rinnai zen combi...comes as standard

 

[old duffer]

 

[old duffer]