British Gas 330+ Condensing Boiler - Display meaning?

[JohnnyUK]

Hi All

Quick question on operating the above, if I may?

I've looked at the manual - it really doesn't answer my question....

There is an LCD display and an Up / Down toggle switch.

I can set the CH flow temp up and down using the toggle switch and having read up on condensing boilers, I understand that this should be around 75C?

Obviously, the display shows the temp going up & down in line with the switch - stay with me here.....

When I let go of the switch, another number (between 50 & 56C) is displayed permanently on the screen.

The exam question is: What does this denote? Is it the temperature of the returning flow?

Thank you!

[B'stard Child]

JohnnyUK said:

Hi All

Quick question on operating the above, if I may?

I've looked at the manual - it really doesn't answer my question....

There is an LCD display and an Up / Down toggle switch.

I can set the CH flow temp up and down using the toggle switch and having read up on condensing boilers, I understand that this should be around 75C?

Why would you think that - Flow temp set to 75 will give at best 55 deg return - anything above 54 deg return means the boiler in normal operation isn't condensing at all so at best 88% efficient

So get the return temp down to below 40 deg and you should be looking at 95% efficient

PS User manuals are normally useless - Installation manuals tell you much more

JohnnyUK said:

Obviously, the display shows the temp going up & down in line with the switch - stay with me here.....

When I let go of the switch, another number (between 50 & 56C) is displayed permanently on the screen.

The exam question is: What does this denote? Is it the temperature of the returning flow?

Thank you!

Is the boiler on but not firing then that's the current temp of the boiler heat exchanger - it should increase when burning gas and decrease when not

BG 330+ is a glow worm boiler BTW

[JohnnyUK]

B'stard Child said:

JohnnyUK said:

Hi All

Quick question on operating the above, if I may?

I've looked at the manual - it really doesn't answer my question....

There is an LCD display and an Up / Down toggle switch.

I can set the CH flow temp up and down using the toggle switch and having read up on condensing boilers, I understand that this should be around 75C?

Why would you think that - Flow temp set to 75 will give at best 55 deg return - anything above 54 deg return means the boiler in normal operation isn't condensing at all so at best 88% efficient

So get the return temp down to below 40 deg and you should be looking at 95% efficient

PS User manuals are normally useless - Installation manuals tell you much more

JohnnyUK said:

Obviously, the display shows the temp going up & down in line with the switch - stay with me here.....

When I let go of the switch, another number (between 50 & 56C) is displayed permanently on the screen.

The exam question is: What does this denote? Is it the temperature of the returning flow?

Thank you!

Is the boiler on but not firing then that's the current temp of the boiler heat exchanger - it should increase when burning gas and decrease when not

BG 330+ is a glow worm boiler BTW

Thanks for the reply.

Many, many "advice" websites talk about 80/60 as the ideal ratio - rightly or wrongly. Also, one of the manuals I found online said set it to 75C.

What should it be set to please and why?

Thanks!

[B'stard Child]

JohnnyUK said:

Thanks for the reply.

Many, many "advice" websites talk about 80/60 as the ideal ratio - rightly or wrongly. Also, one of the manuals I found online said set it to 75C.

What should it be set to please and why?

Thanks!

That’s a whole different ball game…….

Need to know a lot more details about the house, room sizes and rad size and types to even start trying to help but first up lets try a real simple test

Turn the flow temp down to 55

Does the house still get warm?

[JohnnyUK]

B'stard Child said:

JohnnyUK said:

Thanks for the reply.

Many, many "advice" websites talk about 80/60 as the ideal ratio - rightly or wrongly. Also, one of the manuals I found online said set it to 75C.

What should it be set to please and why?

Thanks!

That’s a whole different ball game…….

Need to know a lot more details about the house, room sizes and rad size and types to even start trying to help but first up lets try a real simple test

Turn the flow temp down to 55

Does the house still get warm?

LOL, I see!

Yes, let me have a go!

[B'stard Child]

JohnnyUK said:

LOL, I see!

Yes, let me have a go!

Just one check - it’s combi right?

We are talking about flow temp for CH not for HW

If it’s not a combi then life gets harder as the flow temp will always be a compromise for HW and CH

[JohnnyUK]

B'stard Child said:

JohnnyUK said:

LOL, I see!

Yes, let me have a go!

Just one check - it’s combi right?

We are talking about flow temp for CH not for HW

If it’s not a combi then life gets harder as the flow temp will always be a compromise for HW and CH

There's a thermostat on the hot water tank set for about 60 degrees?

Another wrinkle.....we have a water softener and BG told us to get this specific boiler as it has a stainless steel heat exchanger.

Going through the 9 year old paperwork, this was a lie.....

So, we have softened water going into an alloy heat exchanger - I'm amazed it's lasted this long!

[B'stard Child]

JohnnyUK said:

There's a thermostat on the hot water tank set for about 60 degrees?

Another wrinkle.....we have a water softener and BG told us to get this specific boiler as it has a stainless steel heat exchanger.

Going through the 9 year old paperwork, this was a lie.....

So, we have softened water going into an alloy heat exchanger - I'm amazed it's lasted this long!

I have glow worm boiler (heat only not a combi) been run on softened water for last 13 years (it’s 15 years old this year)

[B'stard Child]

JohnnyUK said:

There's a thermostat on the hot water tank set for about 60 degrees?

Ahh so not a combi but heat only

The fact it heats HW and CH complicates things

Lowest you can run flow temp on HW is 10 deg above target tank temp

So if you want 60 deg HW from the tank 70 deg Flow temp on HW is probably the min you’ll get away with

I don’t keep my HW at 60 - most of the time it’s in the mid 40’s

Once a week take it to 60 for a legionaires cycle

I don’t heat water when I’m doing CH so do a form of manual DHWP