Part L certificate - what is it?

strange

I'm finding out about changing our boiler. I have just spoken to a plumber who reeled off a list of additional changes to comply with the Part L certificate. Does anyone know where I can read the full list of what's needed to comply with part L so I can make sure he's not missed anything. Or added anything.

many thanks,

Strange

adr0ck

all boilers must be SEDBUK bands A or B (a being the most efficient) (unless oil fired ? not sure on this)

sedbuk stands for seasonal efficiency of domestic boilers in the uk...its the official way of measuring the efficiency of domestic appliances

see

https://www.sedbuk.com

relatively good price for boilers etc:

https://www.discountedheating.co.uk

strange

The plumber said that (a) There was a 15mm expansion pipe to the hot water tank that needed to be increased to 22mm and (b) the hot water tank should be replaced with one that has a factory fitted jacket (not the tie-on one that we currently have). He said that this was all to comply with Part L certificate.

I want to find out if he's right but I can't find a list of what part L entails.

The problem with my existing heater (a Thorn Olympic 38/50F) is that one of the heat exchange pipes (the metal things with all the lobes on - right?) is leaking. Does this sound like something that can be replaced? Or must I have a completely new boiler?

str

gromituk

Try searching for spare parts for your boiler on the internet to see if they're available. How old is your boiler and has it hitherto been reliable?

You are right that to comply with Part L, you will need a cylinder which is not only properly insulated, but is "fast recovery" - the heating coil inside it (heated with water from the boiler) is much longer than a traditional type, so the boiler doesn't "short cycle" - switching on and off many times while heating the hot water slowly. This increases efficiency (and gives you a tank of hot water more rapidly).

moneysavingplumber

If it's a Thorn or Thorn-EMI boiler it's likely to be over twenty years old and I don't think anyone makes parts for them. A leaking heat exchanger would not be cost-effective to replace on a boiler of this age.

The ODPM website has some information about Part L. The most comprehensive information is in Energy Saving Trust documents CE30 and CE51 for gas and CE29 for oil. Basically, if in England or Wales, any gas boiler must be Sedbuk A or B rated, some C rated oil boilers are acceptable for now.
Minimum controls are room thermostat, programmer, cylinder thermostat and thermostatic radiator valves for regular boilers and room thermostat and thermostaic radiator valves and timed central heating for combis. All systems should incorporate an automatic by-pass, boiler flow and return temperatures should be set at a twenty degree differential. All systems should be cleansed and treated using the suitable chemicals. The condensate should discharge to a suitable location (not just out onto a lawn) and the boiler's Benchmark card should be filled in correctly. All pipe work in roof spaces and garages should be foam lagged, and so should pipe work immediately connected to a cylinder up to 1 metre away. The installation should be registered with building control via Corgi, for which you will recieve a certificate.

moneysavingplumber

strange wrote:

The plumber said that (a) There was a 15mm expansion pipe to the hot water tank that needed to be increased to 22mm

That would be correct.

gromituk

Seems a bit unnecessary to have a room stat when you've got TRVs and an automatic bypass!

moneysavingplumber

gromituk wrote:

Seems a bit unnecessary to have a room stat when you've got TRVs and an automatic bypass!

The room and cylinder stats provide the necessary boiler 'interlock'. If the room in the house where the stat is located is at 18 degrees already and the stat is set to that, there will be no call for heat. Without the stat, all the time the programmer is on, the boiler will cycle round the bypass even when all TRVs are satisfied, which means less efficiency and more wear and tear on the boiler.

strange

Thanks for all the advice. I managed to restart the boiler last night, but it looks like the upgrade is inevitable - *IF* I really have got a leaky heat exchange. Could anything else be making the inside of the boiler wet? It seems to me that cast iron is not likely to crack or rust within 20 years - or will it?

str

gromituk

moneysavingplumber wrote:

The room and cylinder stats provide the necessary boiler 'interlock'. If the room in the house where the stat is located is at 18 degrees already and the stat is set to that, there will be no call for heat. Without the stat, all the time the programmer is on, the boiler will cycle round the bypass even when all TRVs are satisfied, which means less efficiency and more wear and tear on the boiler.

But therein lies the problem - if one particular room happens to be at 18 degrees, you completely lose control of the temperature in the rest of the house, despite all those expensive TRVs. All you can hope to achieve with a room stat is what you can achieve with a TRV in the same room - control of temperature in that room. But the TRV doesn't deprive the rest of the house of heat when it closes. The only way a room stat can possibly make any sense is if it is located in the coldest part of the house, and you can only ensure that by making sure there are no opening windows elsewhere, and none of the radiators elsewhere can be turned off!

What is needed, instead, is for the pump to come on periodically and the flow/resistance to be measured to determine if any TRVs are calling for heat.

The cylinder stat is a different matter, because it controls a valve which actually controls the temperature it's measuring, and has no other consequences.

invisiblegirls

My heat exchanger has just been leaking.(Stelrad Ideal)
Turn off the electric, gas and water. Drain down
4 Pieces of stud iron to seperate the heat exchanger in two.
4 'o' rings to re seal the leak.
Put back together.
Check the o rings are available first they are hard to find and are not just ordinary ones.
HTH