Installer installed undersized radiators

[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.

 

[tamz]

Probably because the numpty bco was insisting on a 100mm drain test (as on an open drain) which is near impossible on a 50mm wc trap seal (it can be done with a bit of luck if you pump it very slowly) because he knows no better. They are clowns.
If you know you are in the right argue your case with them and go over their head but when you do that you better be sure because the next guy who comes out will have read up on it.

 

[DirksPlumbing]

Probably because the numpty bco was insisting on a 100mm drain test (as on an open drain) ...

Very so. That would make Mira shower trays illegal as well. At least the ones with the supplied trap. And a lot of bath traps, urinals with built in trap, some 6l and virtually all 4.5l liter toilets and and and.

By the way the mentioned building had six flats in it.

 

[tamz]

The final test should be done at 40mm as it can't be any higher than the trap seals but they want it as high as it will go
As i said they are mostly clueless clowns and they are supposed to be regulating us. They are not interested and have very little knowledge of what we do. More interest is a walk through the house for structural things which i can see the poit of.
They no longer concern me as i self cert my work so i am outwith their control even for drain tests.

 

[DirksPlumbing]

More interest is a walk through the house for structural things which i can see the point of.

But where are they when you need them. Been on a site, when I walked in I had been impressed by the extra long beam holding half of the houses roof without additional support to find its left hand side held up by an 2x2 upright.

Walked out to see the site manager (as well to request walls to hang the rads. The guy said to me that was found so when they removed the plaster board and they are not going to do anything about.

As the existing radiators were dangling on bowed brittle 10mm plaster board ready to fall of I just left the place to not be seen again. This "feature" was meant to be left as was as well.

 

[tamz]

But where are they when you need them. Been on a site, when I walked in I had been impressed by the extra long beam holding half of the houses roof without additional support to find its left hand side held up by an 2x2 upright.

Upholding and regulating standard my rse. Like all lines of work there are good and terrible and all the shades in between. Luck of the draw who comes out and even then in many cases there are the backhanders to sway there judgement and blight their vision.
Many years ago in Edinburgh it was common knowledge that it was a fiver a drain test if you were having problems with it standing (the tests were done (or not done) by an ex council plumber)

 

[chris watkins]

It sounds like it is country wide then & I though London was bad but reading you two, it just the same, back in my day there were D or S I's (drainage or sanitary inspectors) & that's all they did, so very difficult to pull the wool over their eye's.
Looking at what they sign off now days, it makes me mad.
The public's main protection & our policeman as far a cowboy workers, don't have a cue & don't care, it seems that all they want to do is take the money.
No enforcement mean the Law becomes an bum.

 

[joni os]

Lets not be unfair to building control officers. Thirty years ago Building Regs was a small book with much useful guidance. Now the document is so complex that by the time you have read it the regs will have changed and you have to go back and start at the beginning. Being required to know a little about everything means they will not be experts in a particular field. In general if treated with respect they will be open to discussion of evidence based practice and prove a valuable source of guidance on new rules. Beware of what you hope for. If they were really clued up on all the rules many plumbers would have costly claims against them for notching of floor joists in the wrong place and in the wrong manner. Electricians please also take note.

 

[SimonG]

A building control department should contain experts in all fields, it would be impossible to expect 1 individual to turn up on site and be proficient in all aspects of what needs to be signed off. We are out in the sticks so there is a lot of all, the bc know nothing about oil, things get missed and don't get picked up until you end up going out to somewhere with an issue and then explaining to the customer it's not right and needs this that and the other doing. The cust then gives it to you in the neck for trying to get extra work from the call out.
IMHO bc should send a 'team' to sign off. But that would be a perfect world.

 

[doitmyself]

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

It's not really oversizing; it's putting in the correct sized radiator, taking into account the required flow and return temperatures. The reason you have to do this is that radiator output varies with flow, return and room temperatures.

Most manufacturers' literature just quote the output according to BS EN442, which specifies temperatures of 75°C/65°C/20°C (flow, return, room). If you run the boiler at say 75°C/55°C (most boiler manufacturers now specify a 20°C differential) the radiator output will be reduced by about 15%. so you will have to install one which is about 20% larger.

Example:

A Stelrad 600 x 1000 K1 produces 1000W at 75/65/20, but only 850W at 75/55/20.
A Stelrad 600 x 1200 K1 produces 1200W at 75/65/20, but only 1025W at 75/55/20.

So if you need 1000W in a room and are running at 75/55/20 you need the 600 x 1200 rad to produce the required 1000W heat.

The rad may be physically larger, but it's not "oversized" as far as the heat is required.

 

[doitmyself]

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 . ... If you've done level3 about modern system design this should have been taught at that stage.

If that's what you were taught, then the teacher needs to go back to school as he was talking nonsense. Unless, of course, you completely misunderstood what he was saying.

 

[chris watkins]

Lets not be unfair to building control officers. Thirty years ago Building Regs was a small book with much useful guidance. Now the document is so complex that by the time you have read it the regs will have changed and you have to go back and start at the beginning. Being required to know a little about everything means they will not be experts in a particular field. In general if treated with respect they will be open to discussion of evidence based practice and prove a valuable source of guidance on new rules. Beware of what you hope for. If they were really clued up on all the rules many plumbers would have costly claims against them for notching of floor joists in the wrong place and in the wrong manner. Electricians please also take note.

A building control department should contain experts in all fields, it would be impossible to expect 1 individual to turn up on site and be proficient in all aspects of what needs to be signed off. We are out in the sticks so there is a lot of all, the bc know nothing about oil, things get missed and don't get picked up until you end up going out to somewhere with an issue and then explaining to the customer it's not right and needs this that and the other doing. The cust then gives it to you in the neck for trying to get extra work from the call out.
IMHO bc should send a 'team' to sign off. But that would be a perfect world.

I am expected to know a lot across a wide range of areas of the industry I work in, it's my job, its what I get payed to do. I am sure the individual BCO do their best & are not supported by there local counsels with either training or funding but that still don't help me & my customers who pay good money to be told "I don't know anything about these systems but if it an't blown up by now it is likely the be OK" oh & by the way here is your bit of paper that says it it approved / registered.
joni I don't go around cutting oversized notches in floor joist so would not have to worry about any claims. I sincerely hope that those who do carry out this dangerous illegal practise would be dealt with in some way don't you ????????????

 

[GasmanxxxR1]

Do you always cut notches in the right places though, thats the hard part imho

 

[chris watkins]

Do you always cut notches in the right places though, thats the hard part imho

Oh yes, I know my cut zones all right.

 

[joni os]

No offence meant Chris, didn't mean you to take it personal. But like Gasman says not only at the right depth but in the right place.

 

[SafeGasInstall]

was it 1/7 only and 150mm away from the walls

 

[chris watkins]

No offence meant Chris, didn't mean you to take it personal. But like Gasman says not only at the right depth but in the right place.

No offence taken nor did I think it was solely aimed at me & you are both perfectly correct important to cut em in the right place.

 

[longboat]

around half of what youd have to pay me, so in my opinion you didnt pay enough to get a decent job done! monkeys and peanuts come to mind. Best to put the other 2.5k towards finishing the job properly and forget the legal battle you canyt afford in the long term.

Five grand for a two up two down! When did you start working for brittish gas?

 

[doitmyself]

I had a new central heating system fitted last year and always thought it was cold but because I didn't really use it, as the property was being renovated at the time, I didn't think much of it.

I've finally got round to measuring the temps this year and it's freezing! The temps are reaching a max of 12C-13C with the heating on. I found out about undersized rads and worked out the required BTUs from online BTU calculators and found out that the rads are nearly all undersized by a fair bit.

So this is really the first time that you have been able to check if the heating works correctly and found that it doesn't, as the rooms do not reach the required temperature. In that case it is not "fit for purpose". Nothing to do with breaking down or developing a fault. It just doesn't do what you want it to do, i.e heat your house to an acceptable temperature.

Is there anything I can do legally being that it has been over a year since the installation?

NO need to get "legal" about it. The installer has not met the requirement that the installation is "fit for purpose", so it is his responsibility to put it right at no cost to you. How long it has been in is not really relevant as the system was "not fit" when it was installed, but you have only now become aware of this.

The obvious solution is larger radiators, which would have cost you more money if put in originally. So a sensible compromise would be to pay the additional cost for the radiators but nothing for his labour.

 

[joni os]

On the room sizes given it would require 1200:1100:and 900 BTU just to cope with heat loss through ventilation.( one and a half air changes per hour). Heat loss through fabric of building to be added to these figures. The ceiling heights suggest this is not a property built with conservation of energy foremost in its design. As others have said get in someone who understands heat loss. ( not just someone with an app. on their iphone). The good news is it is only 3 rads. but when you get this second opinion be prepared to pay for the advice, get a check on the boiler instal and you may well save problems in the future. Unfortunately many in your situation go hunting for advice on the pretext of getting quotes and when they think they have the answer, fix it at the lowest price with the clown who did the original work. If you went to A&E would you want to be treated by a doctor or the hospital porter.

 

[aplombier]

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.

Thank you tamz I did look it up and ur quite correct

 

[aplombier]

If that's what you were taught, then the teacher needs to go back to school as he was talking nonsense. Unless, of course, you completely misunderstood what he was saying.

Nothing wrong with old teacher it was my misunderstanding , ive been using computer generated calculations for years now , and have taken them for granted. And forgotton my basics. Suppose I better re enrol on refresher course