Dell XPS 13 9370 (2018) review
Apologies for bringing a central heating issue to the forum once again.
Can anyone tell me if the regulations allow a 68mm combi-boiler flue pipe to be connected to a 68mm rainwater down-pipe. The down-pipe is coming from a roof gutter to a ground level drain/trap. At times of rain, very little water would come down the pipe, so in theory there should be enough volume in the pipe to take away any plume, similar to an extended pipe from the boiler to atmosphere.
I have raised this question elsewhere, but the answer I received was slightly vague.
I think for this situation, you have to ask a qualified engineer. There are so many (and changing) rules on gas installations that it's easy to transgress. However, why not terminate the flue where it exits the wall - that's how most seem to be these days?
Are you sure this is a flue pipe? and not a Condensate Discharge Pipe.
I think I'd follow otl1's advice. We're in the middle of replacing an oil boiler with a gas boiler, and what is exercising the plumber as much as anything is how to route the flue pipe. It seems there's a lot of things you can't do - and, as otl1 says, the regulations change pretty rapidly - what was true last year may not be true this year.
"Can anyone tell me if the regulations allow a 68mm combi-boiler flue pipe to be connected to a 68mm rainwater down-pipe."
Of course not, you can't be serious.
Do not consider this. You run the risk of getting Carbon Monoxide in to your house from the boil;er and killing all the occupants.
Thank you to those who have so far replied.
What as already been suggested, the regulations are changing all the time, hence my opening remark about the answers I have received so far are rather vague.
The risk of Carbon Monoxide was already considered, but if you look at a flue pipe coming from a combi boiler, through a loft or attic space, then exiting via roof, then the length of this pipe can be a reasonable length, depending on the floor level the combi boiler was installed. The capping (if any) would also make a difference regarding possible restrictions?.
If you consider what I have mentioned, the rain-water down-pipe would be very similar to a flue or vent pipe. With regards to the plastic, then this appears very similar to the existing vent or plume material supplied via the boiler manufacturer. I would suspect that any heat would soon be dispersed, and especially more so in the typical UK climate.
BRYNIT - Its a flue pipe. The 'Condensate' pipe is another issue, that's under further investigation.
Jock1e - Any steam or air content would be discharged to the atmosphere via above roof or open drain. Regarding the "liable to get flooded", this as already happened, but not on the scale perhaps considered. The installer's of the boiler placed the vent (plume) in an upward position, and through a torrential downpour, water come into the boiler and discharged onto a kitchen working surface. Soon remedied by moving the outside flue joint to a downward position.
Jock1e - PS, Posting or checking the internet at 12.48AM isn't unusual for me, especially if I have had a bit of a rough day. Haven't drank alcohol for years, but I did like the occasion party, when the times were right quite a number of years ago:O)
I hope that I have covered any questions, but I can assure you the safety aspect is foremost to my thoughts, hence the possible latest 'regulations' information request. considering all eventualities, I would suspect that the method I have suggested as been tried previously by someone. Perhaps a bit like running roof top rain water or other water types into the wrong drain system?.
I see what you are trying to achieve but there are many reasons for not doing what you are thinking about. Here are just a few.
Against the regs.
Flue consists of inlet and outlet (2 pipes one inside the other) if you connect them to one pipe you will intake the discharge causing your boiler to malfunction.
Plastic downpipe is not heat resistant enough.
If it gets blocked or cant cope with a sudden downpour you will have serious problems.
Just forget the idea for your own sake.
I thought that I would raise the question, because of the vague answers about the latest or previous regulations covering this subject that I was getting, and also knowing previously that there were forum members more knowledgeable on the subject.
Due to a number of problems, its been suggested that I arrange a 'performance test' on the boiler and possibly installation by Worcester Bosch and their engineer. The actual installer of this recent combi-boiler is proving slightly difficult in resolving issues at present!.
I will give this a green tick, but anyone with further advice or relevant information is most welcome to contribute.
"* I arrange a 'performance test' on the boiler and possibly installation by Worcester Bosch and their engineer.*" Absolutely the right thing to do. I know you are having frustrating problems but best not to mess around with flues.
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