Installer installed undersized radiators

[plumber0808]

I wouldn't go there again. He is probably doing this over and over to customers similar to you.
bin him and get the job done correct.

 

[jase158]

my calcs are oversized but better to be over then under

 

[aplombier]

Over sizing radiators can also be just as bad as under sizing as it will affect efficiency and correct temp returns of these new condensing boilers

 

[jase158]

its not just as bad as customer is warm in there own home, which surely is what we are meant to be doing as "heating engineers" however it is still bad as it will cost more then it should to heat the home.
but as someone said before this would be my estimates as i can not see window/ insulation etc.

 

[stevetheplumber]

pay peanuts get monkeys your wasting your time pursuing this legally after a year better to spend the extra for some bigger rads and treat it as one of lifes little lessons always get 3 or 4 quotes to get some idea of what the right price for a job is also always get something in writting as to what your getting for the money and what it will do once fitted

 

[Bronze_tap]

he went for the B&B option then changed his mind and camped🙂

For the first time in his life...
In the 5 pounds Argos single season sleeping bag in the current Lake District conditions (-6C, 35mph), 700m above see level on the eastern side of Skaffel Pike 🙂

Anyway, I assume that any serious user calling himself diyer should know how to do compression/threaded joints.
Have a look on the youtube, get a double convector rad(s), and have a go.
Best with good competent plumber for the first time.
And keep in mind, that plastics doesn't like high flow temperatures for long time... And the underfloor leaks may go undetected for a while...

 

[DirksPlumbing]

Over sizing radiators can also be just as bad as under sizing as it will affect efficiency and correct temp returns of these new condensing boilers

@Chris: You put a like on this comment? Oversizing allows you to lower the flow temperature and therefore minimising heat losses and maximising the gains from the latent heat.

Could someone explain to me the negative effects to expect (except customer spending more on the radiators)? As long as the oversizing is done equally I could not see negative effects at all.

 

[Gray0689]

@Chris: You put a like on this comment? Oversizing allows you to lower the flow temperature and therefore minimising heat losses and maximising the gains from the latent heat.

Could someone explain to me the negative effects to expect (except customer spending more on the radiators)? As long as the oversizing is done equally I could not see negative effects at all.

Well for one building control can and so fail new houses as not energy efficient

 

[aplombier]

It's all about energy efficiency at the boiler so it will condense efficiently and use less gas or use it better thus saving the planet . the flow and returns at the boiler must only have 10c temp difference so if the rads are too big for the boiler then the return to the boiler will be too cold and then the boiler won't condense . Which means you might as well not fit condensing boiler, as stated building regs can now make you rip it all out if they get involved. I'm not the best explainer so hope this is good enough. If you've done level3 about modern system design this should have been taught at that stage.

 

[tamz]

It's all about energy efficiency at the boiler so it will condense efficiently and use less gas or use it better thus saving the planet . the flow and returns at the boiler must only have 20ºc temp difference so if the rads are too big for the boiler then the return to the boiler will be too cold and then the boiler won't condense . Which means you might as well not fit condensing boiler, as stated building regs can now make you rip it all out if they get involved. I'm not the best explainer so hope this is good enough. If you've done level3 about modern system design this should have been taught at that stage.

You are getting things a bit back to front here.

I've also corrected a bit for you

 

[aplombier]

Defo think its 10c but going to check later.
Also what bits back to front tamz

 

[DirksPlumbing]

Defo think its 10c but going to check later.
Also what bits back to front tamz

First of all the lower the return temperature the higher the condensing effect. Anything above 70 degC has to be considered as non condensing range.
The lower the flow temperature the lesser the heat radiation part and therefore the lesser the heat losses in specific in conventional buildings with non reflective membranes, corroded ones or none at all.

The spread only influences the amount of heat distributed into the room. If you use a 55/45 design temperature the spread will obviously be 10 degC. Same on a more extreme 40/30. If you get to lower design temps you will not be able to have a great spread anymore which automatically increases your radiators beyond the increase due to the lower temperatures.

If you go for 60/40 you can keep your rads and pipes smaller but typically your heating pump has to work longer and harder as the friction will be higher. Thus can lead to not being able to use the VP modes on the hopefully A rated pump. The longer boiler run times will also increase losses through the flue. In conjunction with an oversized boiler this will be anything but green.

As far as building control goes they should then fail all surface heatings and heat pump systems? How would they be bothered by bigger and therefore more efficient radiators?
That casts a funny light on those guys waving through uncommissioned boilers being fitted to no standards and not even working.

 

[tamz]

I'll save you the trouble of looking
Older systems were based on an 11º drop. New systems on condensing boilers should be set for a 20º drop.
Condensing boilers only condense when the return temperature is below 55º. This requires oversized rads or a low flow rate and careful balancing.
Big rads that feel cool to touch and low return temperatures mean cheaper bills.

 

[tamz]

Have you got shares in Grundfos Dirk :lol:
Btw most bco's (and i'm sure we have met the same ones) couldn't tell the difference between a paraffin heater and a boiler

 

[DirksPlumbing]

I'll save you the trouble of looking
Older systems were based on an 11º drop. New systems on condensing boilers should be set for a 20º drop.
Condensing boilers only condense when the return temperature is below 55º. This requires oversized rads or a low flow rate and careful balancing.
Big rads that feel cool to touch and low return temperatures mean cheaper bills.

I should learn from you to keep things short and simple.

 

[tamz]

Cut through the bullshyt and get direct to the point is what most people understand

 

[joni os]

Stelrad literature should put this to bed. Mean water temperature / Room temperature, Difference. Means larger rads can produce required heat at lower temperature. Lower temperature means better recovery of latent heat. One of the reasons underfloor heating works well with condensing boilers. Any Building Control who think larger rads mean less efficiency should be challenged.

 

[DirksPlumbing]

Have you got shares in Grundfos Dirk :lol:
Btw most bco's (and i'm sure we have met the same ones) couldn't tell the difference between a paraffin heater and a boiler

I wish I had shares with them. But then it is not exactly an exiting newcomer. Then rather Softing.

Must say I had little contact with building control in Central Scotland. I had been on new builds past Greenock and the islands. The guys there were pretty okay despite the fact you had to pribe them with a fresh coffee on arrival😉.

But the things I have come across in Central Scotland actually made me doubt seriously. Usually handed over buildings.

 

[tamz]

One of my mates is a bco with West Lothian council and i usually have a pint with him of a Friday along with a few other plumbers. We usually educate him on what to look out for (we all self certify so who cares) as he is totally clueless. He admits himself he hasn't a clue about services. Drain tests and asking for copies of the benchmarks are about his limit when it comes to plumbing and gas.

 

[DirksPlumbing]

One of my mates is a bco with West Lothian council and i usually have a pint with him of a Friday along with a few other plumbers. We usually educate him on what to look out for (we all self certify so who cares) as he is totally clueless...

Former workmate had been made to putty all plug holes in the building prior to the drain test and had to remove it afterwards again.