No such word in Latin!
Yourself included, or you would not have made the blunder of confusing quad with quod.Agile said:
QED
Setting Condensing Boiler Flow Temperature
- Thread starter Chris_J
- Start date
QED
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Just to return this disquisition back towards the OP’s question, below is a graph of condensing gas boiler efficiency versus return flow temp to give some idea of what might be expected. I took this from a paper on building temperature control and it gave no information as to exactly what boiler this was measured on, but it’s the only one I have come across.
Forgive me for doing this Mikely but your graph reminded me of a web page with a similar graph and I thought it might be worthy of mention, and a link to the the page as it covers some of the detail behind it without going overboard.
(I don't intend this being 'my graph's better than your graph' competition so apologies if it comes across that way!)
The page also mentions the often-unmentioned fact that whilst condensing generally occurs (or at least starts) below 57C for gas, it is somewhat lower for LPG and oil at 53C and 50C respectively.
Mathew
(I don't intend this being 'my graph's better than your graph' competition so apologies if it comes across that way!
)The page also mentions the often-unmentioned fact that whilst condensing generally occurs (or at least starts) below 57C for gas, it is somewhat lower for LPG and oil at 53C and 50C respectively.
Mathew
Agile said:
Yourself included, or you would not have made the blunder of confusing quad with quod.
QED
I did study latin ( and hated it ! ) but since then I have not needed to speak or often write it and so I made an easy spelling mistake!
Boiler efficiency is important but so is insulation, thermostat setting point and turning off heating in unused rooms.
Tony
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Sorry for jumping on this topic but it seemed relevant I am not sure if I have an issue or not but would like some help, 1st the history
I had a new heating system installed this summer in to a 5 bedroom 3 bathroom house:
• Valiant Eco Tec 637
• 22 New Radiators (Stelrad)
• Un vented hot water system (Glow Worm cylinder)
The pipe work was also upgraded as it was 8mm microbore so house was zoned upstairs/downstairs/hot water, with 22m from the boiler for each zone down to 15mm for the rads. All rads have TRV’s Drayton TRV4’s fitted except for the two upstairs and downstairs hallways near the room stats.
The radiators were specified by myself and the 1st engineer I wanted to do the job, he agreed the size of each rad based upon the room size and the value of all rads came to 22KW, a 37KW boiler was selected to allow for the hot water system and some scope for future expansion. I purchased all the radiators (I was quite happy to install all the radiators and he was happy to just connect to were I had installed but we had to agree that they were the correct size)
Anyway the 1st engineer let me down, don’t know why but it wasn’t just me he let down, so I found a 2nd engineer. Again he was happy for me to install all rads and he would just connect. When he installed all the new pipes
Everything appears to working fine and the house is so much hotter than it was last year where the old system was on 24 hours a day 7 days a week over the really cold period. The old boiler was over 30 years old, leaking and had not been upsized when the house was extended so had to go.
Anyway being new to Condensing boilers and having read this thread I wonder if 637 should be cycling as it does, this is what happens :
• The boiler starts, the pump starts and the gas burner symbol comes on until the temperature reaches 75. This normally takes around 1 mintue15 seconds
• The gas symbol burner then goes out and the pump continue to run until the temperate drops to 49 which normally takes around 3 minutes 15 seconds
• The pump then switches of for around 10 seconds
• The pump then switches back on for around 10 seconds until the burner starts and the cycle starts again
Is this correct for a condensing boiler ? or am I damaging the boiler or not operating it efficiently
I have spoken to the Engineer who installed the boiler and he has told me to keep an eye on it (not sure what that is going to do) his statement is that as I specified the radiators so are they the rights size for the rooms. They were according to the 1st engineer and with all the information I have found. So he hasn’t washed his hands of this entirely but doesn’t seem keen to come back and check it out. So I want to understand if the boiler should be operating like this or I need to push the point
Thanks
I had a new heating system installed this summer in to a 5 bedroom 3 bathroom house:
• Valiant Eco Tec 637
• 22 New Radiators (Stelrad)
• Un vented hot water system (Glow Worm cylinder)
The pipe work was also upgraded as it was 8mm microbore so house was zoned upstairs/downstairs/hot water, with 22m from the boiler for each zone down to 15mm for the rads. All rads have TRV’s Drayton TRV4’s fitted except for the two upstairs and downstairs hallways near the room stats.
The radiators were specified by myself and the 1st engineer I wanted to do the job, he agreed the size of each rad based upon the room size and the value of all rads came to 22KW, a 37KW boiler was selected to allow for the hot water system and some scope for future expansion. I purchased all the radiators (I was quite happy to install all the radiators and he was happy to just connect to were I had installed but we had to agree that they were the correct size)
Anyway the 1st engineer let me down, don’t know why but it wasn’t just me he let down, so I found a 2nd engineer. Again he was happy for me to install all rads and he would just connect. When he installed all the new pipes
Everything appears to working fine and the house is so much hotter than it was last year where the old system was on 24 hours a day 7 days a week over the really cold period. The old boiler was over 30 years old, leaking and had not been upsized when the house was extended so had to go.
Anyway being new to Condensing boilers and having read this thread I wonder if 637 should be cycling as it does, this is what happens :
• The boiler starts, the pump starts and the gas burner symbol comes on until the temperature reaches 75. This normally takes around 1 mintue15 seconds
• The gas symbol burner then goes out and the pump continue to run until the temperate drops to 49 which normally takes around 3 minutes 15 seconds
• The pump then switches of for around 10 seconds
• The pump then switches back on for around 10 seconds until the burner starts and the cycle starts again
Is this correct for a condensing boiler ? or am I damaging the boiler or not operating it efficiently
I have spoken to the Engineer who installed the boiler and he has told me to keep an eye on it (not sure what that is going to do) his statement is that as I specified the radiators so are they the rights size for the rooms. They were according to the 1st engineer and with all the information I have found. So he hasn’t washed his hands of this entirely but doesn’t seem keen to come back and check it out. So I want to understand if the boiler should be operating like this or I need to push the point
Thanks
Note forum rule 6.
You would be better off starting a new thread anyway.
You would be better off starting a new thread anyway.
I have alerted the moderators and asked this to be moved to a new topic. It doesn't sound right though.
Sorry will start new thread
I'm pretty sure I've chosen the right rad sizes from the catalogue, but I can double check. They are definitely the ones without the fins on the back. Unfortunately, they were brand new when we moved in, so I was loathed to replace them.
I calculated the heating requirement based on the calculator you linked me to, but I did not subtract the the DHW allowance.
I've always thought that the radiators were undersized, however, I don't experience any boiler cycling. The new boiler has anti-cycle, but the old one (Icon 23T junk) still didn't have cycling problems. The only slight problem I notice is the lounge taking quite a while to warm up, but we have exposed wooden floors that aren't insulated underneath. Luckily, I have a wood burner that takes over and causes the TRVs to shut.
I wonder why the previous owner put in undersized rads???
In that case you have a heating requirement of about 11kW but only about 4kW of rads. The boiler can modulate down to about 6KW.
What's the output of this? Was it there when you moved in? If so it could account for the undersized rads.
If you decide to upgrade your rads, you will probably need to fit 600mm high ones as 450mm double convectors will not give enough output.
Well, I'm an idiot. Made some assumptions here - and you know what they say about assumptions...
Anyway, after checking the size and type of the rads PROPERLY, the outputs are 1200W and 800W. Therefore, the correct calculation is as follows:
(1200x4)+(800x3) = 7200W
plus a towel rail of unknown output, so CH output is about 8kW.
Still a little undersized, but much closer to the 11kW requirement.
Regarding the stove, it was something that I fitted when I moved in. Nothing to do with the heating output, I just always fancied having one and the cat/dog/missus love it! (I should watch how I write that!)
Output of stove is 8kW max.
Anyway, after checking the size and type of the rads PROPERLY, the outputs are 1200W and 800W. Therefore, the correct calculation is as follows:
(1200x4)+(800x3) = 7200W
plus a towel rail of unknown output, so CH output is about 8kW.
Still a little undersized, but much closer to the 11kW requirement.
Regarding the stove, it was something that I fitted when I moved in. Nothing to do with the heating output, I just always fancied having one and the cat/dog/missus love it! (I should watch how I write that!)
Output of stove is 8kW max.
So they were not 1200mm x 450mm and 600mm x 450mm flat panels without fins? What were they?
Useful in the present very cold weather.
Could the heat from the stove be affecting the wall thermostat - turning it off too early?
Radiators are type K1 (single panel with fins) size 1200x600 and 600x600, giving 1200W and 600W respectively.
Stove is excellent in the winter, as you say. I've positioned the thermostat such that it is not affected by the heat from the stove. The stat sits in the hallway and I make sure the door is always shut. This way, the stat basically keeps the upstairs rooms at the correct temperature, and the TRVs in the lounge make sure it doesn't become blisteringly hot if the rest of the house still needs heat.
Seems to work well, but I need to get the TRVs set right, as they're going off a little early still.
Stove is excellent in the winter, as you say. I've positioned the thermostat such that it is not affected by the heat from the stove. The stat sits in the hallway and I make sure the door is always shut. This way, the stat basically keeps the upstairs rooms at the correct temperature, and the TRVs in the lounge make sure it doesn't become blisteringly hot if the rest of the house still needs heat.
Seems to work well, but I need to get the TRVs set right, as they're going off a little early still.
Are you sure it's not the wall stat turning the boiler off before the rooms with TRVs have reached temperature?
You can overcome this by closing the valve on the rad in the hall a bit at a time, so the hall heats up slower than the other rooms.
You could be right, yes.
Do you mean close down the normal valve or the lockshield?
Do you mean close down the normal valve or the lockshield?
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