Whats this nonsense?

[JimmyS]

The most important temperature is that of the return water to the boiler. The lower it is, the better the temperature difference to the heat source and therefore the higher the heat transfer. It follows that lowering the flow temperature will help but you always need to know what your system was designed to operate at. Conventionally heating was designed to operate with 80 C flow and either 70 or 60 C return and the radiators would be selected to suit. Condensing systems are often designed with a flow of 60 C and a return of 40 C which gives a good compromise between boiler efficiency and radiator sizes (in a house with modern high insulation levels). If you subsequently reduce the flow temperature then the heat output from the radiators drops considerably ( look at radiator selection data from the manufacturers and there will be a whole load of correction factors to apply to the outputs for differing temperature. These are based on the difference of the mean water temperature to the space temperature). This is why underfloor heating is good with condensing boilers as it will probably have a maximum flow temperature of 45 C and a corresponding very low return temperature and hence the boiler will operate continuously in its condensing mode and therefore very highest efficiency.
Also important to ensure that the flow temperature remains sufficiently high to heat the domestic hot water if this is provided by a cylinder.
Would be interested to see the details of the Hive thermostat if you have them.

Directly weather compensated domestics will normally ramp up the flow temp on a hot water demand sign to overcome this issue.

 

[AVI_8]

Would be interested to see the details of the Hive thermostat if you have them.

I have the hive recordings, tells you the temperature 24/7 and the boiler operating timeline
A lot of what you said corresponds to what I read, not sure what details of the Hive thermostat you mean, but before I wired it in I could select the heat output from the boiler, I could turn it down with a dial, since wiring in the hive thermostat it’s either on or off, full power from the boiler until the stat cut off then off. The radiator thermostat gauge selection has no effect on the output temperature of the boiler.
Apologies to the OP it wasn‘t my intention to take over your thread.

 

[JimmyS]

Hive is really just a programmable start normally wired in as you would any stat. You should still be able to adjust the boiler flow temp.

 

[colnerov]

Is this along the lines of heating a room with a candle in an upturned flower pot? As fas I can see it's another17 litres of water to heat up.

Colin

 

[AVI_8]

Hive is really just a programmable start normally wired in as you would any stat. You should still be able to adjust the boiler flow temp.

It’s an Ideal Vogue C40, guessing that the tiny spindle of the temperature dial selector has stripped again, its happened twice before and is clearly a design fault, looks like I need to order a new dial selector

 

[addjunkie]

Is this along the lines of heating a room with a candle in an upturned flower pot? As fas I can see it's another17 litres of water to heat up.

Colin

The additional 17ltrs of water…..mini heat store tank perhaps. Bigger volume holds its temperature far more efficiently than a small volume Of just water filled pipes.

 

[dobbslc]

Apologies to the OP it wasn‘t my intention to take over your thread.

@AVI_8 crack on! Its interesting stuff especially the bits about condensating boilers! I need to check flow and return temps on my system as I've never really set it up since I built it.
This thread was a bit of a laugh about magic boxes saving power!

 

[Wozzaaah]

Let’s open the magic box and see what’s inside……

 

[8ob]

This box of tricks is doing what the Theta return mixing valves did with commercial systems over forty tears ago, flow/return mixing reduces the boilers heat cycles by raising the return temperature, the box of tricks has a vent as well which may help quieten a system. Not saying its necessary on a small system but return mixing is probably still done on larger systems.

Bob

 

[Mikes]

That's a good video but his explanation of it as a low-loss header is incorrect. Whilst it does indeed act as a low-loss header, the boiler primary flow should always be greater or equal to the sum of the secondary circuit flows otherwise you will end up with possible reverse flow. The benefit of a low-loss header is that it allows the boiler primary flow to be unaffected by anything on the secondary circuits (TRVs closing etc) and therefore keeps the boiler happy. The downside of this is that each secondary circuit also needs a pump as well as the boiler pump and therefore more complication / cost etc. Only really worth considering on large houses where you want to have multiple secondary zones.
Larger systems and those in commercial buildings have generally used a weather compensated mixing valve to reduce the flow water temperature according to the outside temperature. Not so common now with the move to variable volume pumping systems - but that's another whole topic!
In reality, that particular magic box won't save you money and there are far better energy savings to be had.

 

[Blobber]

I read an article recently which said that if you’ve a condensing boiler it will become more efficient if the outflow temperature is reduced to around 60 degrees, I thought it try it but I’ve a hive thermostat wired in and turning the output temperature down on the boiler has no effect, it heats at full power until the stat sees 17 degrees then shuts off.
This device appears to claim that it will reduce the output temp to 60 degrees, I’d be interested to know from a heating engineer if there’s any truth in the claim that a condensing boiler is more efficient with a lower output temperature and if so how can that be achieved

I was always under the impression that condensing boilers need to run at full chat to be efficient otherwise they wont condense?

 

[JimmyS]

I was always under the impression that condensing boilers need to run at full chat to be efficient otherwise they wont condense?

You just want a low return water temp. They dont need to run full belt.

 

[slim_boy_fat]

https://hydrogardlegalservices.co.uk/news/f/magic-well-it-made-your-money-disappear-didnt-it

 

[Alan Reynolds]

It’s like those useless gadgets you plug in to ‘save’ you electricity AND gas on some of the adverts! They’re just a flashing led and actually COST you money. You are encouraged to buy several to ‘increase’ your savings.
It’s the same with the OBD port gadgets that ‘remap’ your ecu and save fuel. But people buy them!

 

[brightspark]

It’s like those useless gadgets you plug in to ‘save’ you electricity AND gas on some of the adverts! They’re just a flashing led and actually COST you money. You are encouraged to buy several to ‘increase’ your savings.
It’s the same with the OBD port gadgets that ‘remap’ your ecu and save fuel. But people buy them!

theres plenty of them one born every minute

 

[Maker]

My old 2009 rig used to run very hot. Dual GPUs at around 100deg c. Each cpu used to run at about 90 kicked a shed load of heat out of the back like having a fan heater under the desk

I used a dual Xeon server as a desktop for a few months, certainly didn't need the heating on with that running, you did need earplugs however.

 

[Seadog]

It’s like those useless gadgets you plug in to ‘save’ you electricity AND gas on some of the adverts! They’re just a flashing led and actually COST you money. You are encouraged to buy several to ‘increase’ your savings.
It’s the same with the OBD port gadgets that ‘remap’ your ecu and save fuel. But people buy them!

Bigclive looked at one of those recently.