Ideal Vogue combi. Range rating, or the lack of ......

[vulcancontinental]

I'm quoting a two year old post below. It seems categorical that the 75% mentioned is 75% of the range rated maximum. I imagine we would have an ignition sequence (3 or 4 seconds?) at perhaps 50% of full output, followed by maybe 10 seconds also at that output to check the flame is stable. Then the boiler drops to 75% of range rated output, then gradually ramps up. As regards some other manufacturers, this info is not easy to get hold of. I have no idea how Worcester Bosch and Ideal do it.

Both the software and heat exchanger are different between the Vision S and the Vibe Max.

The latest software starts the boiler at 60% of the range rated output and that’s the max for 15 minutes.

In that time the flow temperature will modulate but the max output is capped.

If demand continues uninterrupted for 15 minutes the software will increase the 60% to 70% as continued demand from external controls indicates the need for space heating. This time and power incremental increase repeats until either the boiler setpoint is reached or external control contacts open.

As far as I’m aware this is the only boiler range on the market that does this until our new models are released.

It’s quite logical and increasingly necessary as heat loss from properties is reducing and the vast majority of firings are restarts from a hot state, not from cold.

Relying on modulation alone doesn’t work particularly well as even the high modulating boilers which will drop to less than 2kW if hot refire at 75% of max meaning it hits setpoint almost immediately resulting in micro-firing rapidly. Their software has had to be refined to try to get over that situation.

 

[MNW67]

Both the software and heat exchanger are different between the Vision S and the Vibe Max.

The latest software starts the boiler at 60% of the range rated output and that’s the max for 15 minutes.

In that time the flow temperature will modulate but the max output is capped.

If demand continues uninterrupted for 15 minutes the software will increase the 60% to 70% as continued demand from external controls indicates the need for space heating. This time and power incremental increase repeats until either the boiler setpoint is reached or external control contacts open.

As far as I’m aware this is the only boiler range on the market that does this until our new models are released.

It’s quite logical and increasingly necessary as heat loss from properties is reducing and the vast majority of firings are restarts from a hot state, not from cold.

Relying on modulation alone doesn’t work particularly well as even the high modulating boilers which will drop to less than 2kW if hot refire at 75% of max meaning it hits setpoint almost immediately resulting in micro-firing rapidly. Their software has had to be refined to try to get over that situation.

Thanks, very interesting. So what is the ignition sequence e.g. what % of full power (or range rated power) does it ignite at, and how long (if at all) does it stay at that power to check flame stability before going down to 60% of range rated power? I couldn't work it out from the manual. (Maybe it is 3600 rpm which is about 45% of full power? but how long does it stay there)

Just found this but have no idea what slow ignition is:

 

[gas112]

Here’s a tip for you gas: ring Ideal and get them to check the serial number before installing.

Perhaps you didn’t know that every gas boiler has a unique serial number.

Glad to be able to help, is there anything else I can help with?

oh deary deary me you think that every installer knows about the recall you really are as daft as you sound . Loads of guys may only visit a merchants every few months may not speak to anyone while they are in there .We have not been contacted on mass about this recall same as the vast majority of recalls it ends up as word of mouth there is well over 6 figures of registered guys out there .
As i keep telling you stop talking about stuff you know nothing about

 

[vulcancontinental]

Thanks, very interesting. So what is the ignition sequence e.g. what % of full power (or range rated power) does it ignite at, and how long (if at all) does it stay at that power to check flame stability before going down to 60% of range rated power? I couldn't work it out from the manual. (Maybe it is 3600 rpm which is about 45% of full power? but how long does it stay there)


View attachment 336540

Just found this but have no idea what slow ignition is:

View attachment 336539

Ignition speed at firing to ensure reliable ignition (higher than minimum) then it rapidly modulates down dependant on the flow and return thermistor readings.

Once alight the fan speed can reduce but ignition has to be reliable.

Fan speed determines output and that will not rise above 60% of range-rated maximum for 15 minutes, then 70%, then 80% etc until the sequence is broken.

Temperature is regulated by flow, hence the modulating pump and gas flow.


Vokera are owned by Riello probably the premier burner manufacturer, certainly one of the most respected; burners are not just a series of holes punched into a stainless steel tube.


Fans will turn at 0 rpm to say 9000rpm but 0% and 100% would be measured from the lowest fan setting to the highest, not stationary to the maximum the fan is capable of.

There are some tweaks possible for certain situations, particularly DHW when the boiler starts in a different manner. One would be say when the DHW had reached setpoint, most boilers stop then relight as normal. One of the features of that boiler is to reduce DHW temperature oscillation by keeping fan rotation but ending fuel to burner at DHW setpoint. This means there is reduced lag in speeding up fan to ignition speed before fuel is reintroduced. It also can help with incoming 'cold' water that is hotter than normal in a hot country or preheated by solar. Stabilizing DHW at the tap.

You are unusual in noticing this, most installers and customers have no idea.

 

[Johntheo5]

Ignition speed at firing to ensure reliable ignition (higher than minimum) then it rapidly modulates down dependant on the flow and return thermistor readings.

Once alight the fan speed can reduce but ignition has to be reliable.

Fan speed determines output and that will not rise above 60% of range-rated maximum for 15 minutes, then 70%, then 80% etc until the sequence is broken.

Temperature is regulated by flow, hence the modulating pump and gas flow.


Vokera are owned by Riello probably the premier burner manufacturer, certainly one of the most respected; burners are not just a series of holes punched into a stainless steel tube.


Fans will turn at 0 rpm to say 9000rpm but 0% and 100% would be measured from the lowest fan setting to the highest, not stationary to the maximum the fan is capable of.

There are some tweaks possible for certain situations, particularly DHW when the boiler starts in a different manner. One would be say when the DHW had reached setpoint, most boilers stop then relight as normal. One of the features of that boiler is to reduce DHW temperature oscillation by keeping fan rotation but ending fuel to burner at DHW setpoint. This means there is reduced lag in speeding up fan to ignition speed before fuel is reintroduced. It also can help with incoming 'cold' water that is hotter than normal in a hot country or preheated by solar. Stabilizing DHW at the tap.

You are unusual in noticing this, most installers and customers have no idea.

It would be nice to see trends one of these boilers firing up from a very low WC requested flow target temperature of say 35 to 40C, modulation, fan speed, flow& return temps etc.

 

[MNW67]

Large bore or small bore exchanger?

heat exchanger are different between the Vision S and the Vibe Max

I see the Vibe is stainless steel. Is it classed as large or small bore? Does it pass straight through like a coiled hosepipe or is it a complex pattern like below?

 

[vulcancontinental]

I see the Vibe is stainless steel. Is it classed as large or small bore? Does it pass straight through like a coiled hosepipe or is it a complex pattern like below?

View attachment 336577

Large bore, no cross welds or manifolds or constrictions. The retarder makes it 2 pass and ensures the flue gases engulf the whole of the tube, throughout it's length.

 

[MNW67]

Large bore, no cross welds or manifolds or constrictions.

A poster commented a little while back that Worcester Bosch had launched a lower priced boiler with a stainless steel heat exchanger. I think I've tracked it down. It's a new model by the same people who make the heat exchanger in Vaillant/GlowWorm/Ideal/Baxi etc., but this one has a large bore continuous tube design. Maybe they copied yours! I'm sure this is the one because it has a very distinctive front.

https://sermeta.com/en-gb/product/mhytech/

 

[vulcancontinental]

It would be nice to see trends one of these boilers firing up from a very low WC requested flow target temperature of say 35 to 40C, modulation, fan speed, flow& return temps etc.

I just did a couple of videos, one with and one without WC but I can't emulate a house ticking over.

Our test rigs get rid of the heat through a plate heat exchanger so it's like a range rated 8kW combi trying to heat hot water therefore the return is so low the boiler is always running at an 8kW fan speed to try to get some equilibrium between flow and return.

It fires at 5,500 then immediately ramps down to below max but comes back up again. With the heat dump turned almost off it reached the set flow temperature (58degrees) then dropped to minimum happy to run continuously.

 

[Johntheo5]

Getting a boiler away with a target temp of 58C is much less of a challenge than with a target temp of (WC) 35C/40C, I often thought that overriding the burner trip at targettemp+5C (and set the trip to the max flowtemp allowed+5C, say 85C) for a set period, say 1/1.5 minutes or so until any boiler settles down would be a big help to avoid this rapid recycling, once the override is removed the boiler would still recycle "normally" if its minimum output is greater than the heat demand, but I suppose if it were that easy they would all be doing it?.

 

[MNW67]

Getting a boiler away with a target temp of 58C is much less of a challenge than with a target temp of (WC) 35C/40C, I often thought that overriding the burner trip at targettemp+5C (and set the trip to the max flowtemp allowed+5C, say 85C) for a set period, say 1/1.5 minutes or so until any boiler settles down would be a big help to avoid this rapid recycling, once the override is removed the boiler would still recycle "normally" if its minimum output is greater than the heat demand, but I suppose if it were that easy they would all be doing it?.

I'm sure I read about a boiler with an option to do exactly that.

 

[Mr.B]

If we've finished with the original topic - and I think we have - would you fellas like to start another thread to continue with your deliberations ?

 

[vulcancontinental]

Getting a boiler away with a target temp of 58C is much less of a challenge than with a target temp of (WC) 35C/40C, I often thought that overriding the burner trip at targettemp+5C (and set the trip to the max flowtemp allowed+5C, say 85C) for a set period, say 1/1.5 minutes or so until any boiler settles down would be a big help to avoid this rapid recycling, once the override is removed the boiler would still recycle "normally" if its minimum output is greater than the heat demand, but I suppose if it were that easy they would all be doing it?.

It's tricky to set up weather com because of the above and there are calculations made on the weather data gthat slow things down. I think I'll simply lock the boiler stat to 45 and restrict the flow through the boiler to raise the return temp because if the return is cold then the boiler just runs trying to achieve a higher flow.

 

[vulcancontinental]

If we've finished with the original topic - and I think we have - would you fellas like to start another thread to continue with your deliberations ?

I hope you'll bear with us otherwise we're swapping between threads to find older posts.

 

[Mr.B]

Be my guest then.