Gas Boiler help

needhelp1_2

Hello,

My boiler has just packed up and I have had a Gas Safe Engineer around to give me a quote for a new boiler.

I have been told that as the mains gas pipe is 18mm I can only have a 24kW boiler installed or have new pipework too which will be very expensive.

I have been having a look at boilers online and it appears that even 24kW combi boilers need 22mm piping.

I have measured the pipe diameter myself and it measures 21mm (outside) so I am now confused. I assume the engineer was referring to the inside diameter??

Please can someone knowledgeable tell me if my pipes are definitely suitable for a boiler that asks for 22mm mains pipes and whether I risk voiding the manufacturers warranty if I go ahead and use the current pipes.

Many thanks
needhelp1

Pennypins

Hello,

You need to find out if the pipework is iron or copper.

Copper piping has a outside diameter of 15 or 22mm.

Iron piping is measured in inches, and is measured from the inside at 20mm for 3/4" and 15mm for 1/2".

It doesn't matter about the size but you are only allowed one millibar drop in pressure from the gas meter to the last appliance on gas.

So you may have to strip out the pipework from the gas meter to the boiler and re-run a bigger size either 22mm or 28mm depending on what the new boiler requires and distance from the meter and how many bends or elbows appear in the pipework. And the pipework has to be run above floor level (not under floorboards).

Hope this helps.

needhelp1_2

Thanks Pennypins for your very helpful reply!

The pipes are copper as far as I can tell - at least they are copper coloured - but the outside diameter is only 21mm! They are very old! There are three elbows visible.

The pipes come into the house an under the floorboards on the first floor- the engineer made no mention that any new pipes would have to be over floorboards. Is there no way the new pipes could just be laid where the old ones currently lie?

Many thanks again

Pennypins

The reason why it measures 21mm is it's possibly imperial copper as you say it's very old pipework. You can run pipework through a floorboard with sleeves but cannot run the pipes under the floorboards because the pipes require ventilation and to run pipework under floorboards is now illegal due to the gas regulations.

This is the reason why most gas pipes are run around the outside of the house nowadays.

needhelp1_2

Thanks Pennypins you've been a great help!

Hopefully I can keep the current pipes and have a 24kW boiler installed. I think that I will get some more quotes now that I know what to ask!

sandhu40

Pennypins wrote: »

The reason why it measures 21mm is it's possibly imperial copper as you say it's very old pipework. You can run pipework through a floorboard with sleeves but cannot run the pipes under the floorboards because the pipes require ventilation and to run pipework under floorboards is now illegal due to the gas regulations.

This is the reason why most gas pipes are run around the outside of the house nowadays.

Hi,

you can run gas pipework under floorboards. In fact you can run pipework along a floor and bury it in concrete. It does not need ventilation and this advice you have been given is wrong- sorry.

If the pipework is not at least 22mm in copper it will need replacing, possibly to 28mm. How many metres is it from the gas meter to the boiler location and how many other gas appliances are running of the meter? Or even better, how many are teed off the pipe run from the meter to the boiler?

Pipework can go under floorboard as long as strict regulations are met. It is not any more dangerous than running pipework outside your property. Notches can be made in joists or holes cut through.

Let us know and we can give you more advice.

needhelp1_2

Hi sandhu40,

Phew - There is nowhere else for the pipes to go other than under the floor boards - I really appreciate your reply!

The gas pipe runs from the meter box, which is housed at the front of the property, to the back of the house, via the first floor. The distance is about 8m straight plus 1.5m at either end so 11 altogether.

The only other gas appliance is a cooker (gas hob and oven). The shower is electric. There are 11 radiators.

I am a bit concerned that the engineer told me that I didn't need to replace the pipes - I am not sure he wants the extra workload. I definitely need to get someone else to look at it before I do anything.

Thanks again for your advice!

sandhu40

22mm pipework will probably be enough for a 24KW boiler and can easily handle the heating. It isn't a matter of if the engineer wants to change the pipework - he will have to upgrade it to at least 22mm to comply with the new regulations. As has been stated the maximum allowed drop over the pipework is now only 1mb, this will be more with a smaller sized pipe.

What you will compromise on though is hot water. The flow will be around 9 or 10 litres per minute which isn't alot and it all depends on what you expect as a minimum. A larger output boiler isn't alot more, just 350 in some cases and will increase you hot water output.

What is your ideal budget? I can recommend a good boiler for your budget. Remember, if you currently have any kind of homecare service you can look at cancelling that and save an average of £19 per month. With some boiler manufacturers offering 5 years parts and labour guarantee you can save alot of money - assuming the boiler is installed to all required standards of course.

Let me know your total budget and I can recommend a boiler and the labour you should get charged.


edit,

When was your meter moved outside? It is possible that the pipework is already 22mm. That would be my guess. It is rare for a meter to be outside and running off 15mm.

needhelp1_2

Hi again,

I live in an old Victorian Terrace near Norwich. We only moved last year so I have no idea if the meter was moved. I measured the pipe to be 21mm (diameter) but the engineer said we had 18mm piping - I guess that is the internal measurement. He definitely said that we could get away with not replacing the pipes and get a 24kW boiler. The current one is 28kW combi and he said it should never have been installed.

To be honest I am not looking to spend heaps of money on this. Our boiler was working until last week when it sprung a leak and so I called the engineer in to fix it. He replaced a part and when he refilled the boiler it wouldn't work properly - it keeps cycling on and off, ie firing up and then turning off, every few seconds. The radiators are eventually warming up but to nowhere near what they should and the hot water is also taking a lot longer to heat up when I turn on the tap. He said it was a blockage and tried de-sludger and then stronger desludger and the boiler manufacturer doesn't know what else to suggest so I have been offered the choice of it being taken apart and parts replaced or just to replace the whole thing which I was thinking about anyway, since it is 8 years old, is noisy and needs to be moved to a different wall in the next few months for a kitchen remodel.

Anyway, I was quoted about £1500 to replace and install the boiler with a Baxi condensing boiler 24kW. On top of that we need 7 rads replaced as they are very old and rusted - haven't had exact quote for this yet. He quoted £400 for pipework if we wanted to upgrade to 28mm.

Many thanks for all the helpful advice sandhu40!

needhelp1_2

Hi mealticket

Yes, I am talking about the pipe which leaves the meter and travels through the house to the boiler.

I know that the old boiler was installed in 2001 but the workmanship is very poor, more like DIY although I do have paperwork which shows it was installed by someone who was CORGI registered.

Thanks

sandhu40

hi again,

£1500 is perhaps slightly on the expensive side. The baxi model, depending on which model could have cost him less than £600. Adding bits of peices that are needed materials will cost aound £650. So in effect you could be agreeing to be charged £850 for a days labour. It should take the whole day to move the boiler to another wall and make good. He'll possibly come back the next day and flush the system again depending. You need to enquire what model the boiler is. Baxi are not very good models and I would not recommend that to one my customers. Some Glow Worms are cheaper and better. My advice is to spend £00 more on the boiler and get a much better boiler.

The £400 for the labour is also slightly expensive if its going to be run on the outside of the property. It wouldn't take more than half a day if done properly.

Get everything in writing and find out exactly what you are getting. If you are happy and confident with the installer than my advice is to go with him but thats after you have 3 quotes.