Yes that's a Bypass, if all zones are shut, it has a place to flow round - most boilers allow for a 30-60 second pump overrun to remove the heat out of the heat exchanger within the boiler, but two ports shut instantly. When they close the pressure increases and forces past the bypass to flow down it.
From what I can see you have a heart only boiler with an S plan heating system.
Could be a lot of reasons the pipe splits but more than likely just because of the layout of your house.
What are the issues you are having with the heating?
It's been non stop issues tbh. Current one is that the pressure is dropping 0.2 bar per day, so I assume there is a leak somewhere. But I can't find it. I pumped up the expansion vessel today because it was a bit low, but I've never seen the pressure high in the system, so I don't think it's opening the relief valve and losing water that way.
I just can't understand why that pipe would split in two if the only sensible place it would be going is back to the boiler! Suppose it could be one of the other return lines (from zone 1 or zone 2). Odd that it's done below the ceiling since none of the rest is!
It's difficult to see from the pictures where the pipes go, but could it be the cold water feed? That would normally have a pressure relief valve on it to limit the incoming pressure from the mains.
So the green line comes off the supply side from the boiler/pump, goes past the pressure gauge, then the regulator, then the return from the hot water ties in. That combined line then goes up into the ceiling as per photo 3, but it splits into two first.
Cold water feed is obvious and I left it out here to just focus on the heating system. It does have its own regulator.
Relief valves are all clear and separate. One on heating system between boiler and pump and 2 on hot water side (one off the cylinder and one off the inlet line to cylinder).
I can't explain how it all works but if your concern is that your radiators aren't getting hot surely after turning the heating on then that's normal.
The heating will only kick in once the water tank is at full temperature. That takes about a day for me. And the radiators never get more than warm even then. It takes a couple more days for the house to reach a comfortable temperature.
It sounds like you've got much bigger problems than me!
My current issue is loss of pressure. Can't find a leak so suspect there could be one in the boiler. But I've had a bunch of issues over the years so just trying to understand the system a bit more!
**Please help keep AskUK welcoming!**
- When replying to submission/post please **make genuine efforts to answer the question given**. Please no jokes, judgements, etc. If a post is marked 'Serious Answers Only' **you may receive a ban for violating this rule**.
- **Don't be a dick** to each other. If getting heated, just block and move on.
- This is a strictly **no-politics** subreddit!
Please help us by reporting comments that break these rules.
*I am a bot, and this action was performed automatically. Please [contact the moderators of this subreddit](/message/compose/?to=/r/AskUK) if you have any questions or concerns.*
10 Comments
MaleArdvark@reddit
intollerablepleasure@reddit
BrotherClive@reddit (OP)
nivlark@reddit
BrotherClive@reddit (OP)
kirkum2020@reddit
BrotherClive@reddit (OP)
kirkum2020@reddit
nivlark@reddit
AutoModerator@reddit