Help wanted to identify pipework

[niallcook]

Wonder if any of you clever people can help identify the various parts of the CH/HW system pictured in the image below.

Basically, Pipe A comes out of the top-left of the boiler, into a Grundfos pump, branches then runs to a valve. I am pretty sure this is the CH flow (it's a single pipe system).

Pipe B branches off Pipe A via a second valve. I'm assuming this is the HW flow.

Pipe C also branches off Pipe A via a radiator-type valve (seems to be half open). It runs down to a bottom-right boiler connection and off upstairs along with the other pipes.

Pipe D comes out of the top-right of the boiler. Not sure if this is flow or return or whether CH or HW.

Pipe E is not shown in the pic, but connects to the bottom-left of the boiler. I'm assuming this is the CH return.



So, with all that, some questions:

• What is the purpose of the radiator-type valve connecting pipes A and B to type C? Should it be open or closed?
• Could this layout be easily converted to a two-pipe system?
• Are my assumptions about flow/return CH/HW correct?
• What are the most likely purposes of pipes C and D?

Thanks for any help. Feel free to ask questions to help clarify (I'm not a trained plumber, so bear with me).

 

[franky]

Can you put up more pics from the boiler to these pipes also can you take off the insulation around pipe c and d.
It would just help a bit thanks

 

[Zorro]

C looks like a bypass, due to the bypass valve

 

[niallcook]

C looks like a bypass, due to the bypass valve

Thanks. What would it by bypassing? If the radiator-type valve controls this, should it be open or closed?

 

[niallcook]

Can you put up more pics from the boiler to these pipes also can you take off the insulation around pipe c and d.
It would just help a bit thanks

Thanks. Have updated the original post with some further pics.

 

[franky]

Right don't touch the bypass thats probably set to be open a certain amount.
You have flow and returns Ds probably a return
what is it you'r trying to do with the system?

 

[niallcook]

Just trying to fathom it out. A lot of the pipework is hidden under floorboards and it's an old place so not easy to start lifting things up. Ultimately trying to get it running more efficiently as it's burning oil like there's no tomorrow and many of the upstairs rads (which seem to be on the ends of the single pipe runs) are still cold. Also, if I end up replacing with double pipe, I'd like to do as much of the pipework I can myself so want to understand what does what a bit better.

 

[franky]

Have you tried getting someone out to service the boiler, also a powerflush for the system. I very much doubt the system is a one pipe system so you won't have to change pipework.

 

[niallcook]

Have you tried getting someone out to service the boiler, also a powerflush for the system. I very much doubt the system is a one pipe system so you won't have to change pipework.

Hi. It's been serviced every year and I think powerflushed about 3 years ago. It is definitely a one pipe system (only one pipe running at floor level underneath rads and this connects to top of one side of rad and bottom of other).

 

[noleaksihope]

old one pipes systems are notoriously bad heaters. is it screwed iron pipework on the single pipe runs ? seen 2" iron reduced to 1/4" bore with solidified deposits. no amount of powerflushing is going to remove it or improve circulation.

get a heating engineer in to give you some advice. explain you may wish to carry out the pipework etc yourself but you would be prepared to pay a consultancy fee for his expert knowledge and opinions.

heat losses on any long uninsulated pipe runs aren t helping the efficiency of the system , especially under the floor.

edit - is your existing boiler room sealed or open flued ?

 

[niallcook]

old one pipes systems are notoriously bad heaters. is it screwed iron pipework on the single pipe runs ? seen 2" iron reduced to 1/4" bore with solidified deposits. no amount of powerflushing is going to remove it or improve circulation.

Yes, that's kind of what I thought. Even to my untrained eye, the pipe runs do seem very bizarre (go from boiler in lean-to up to loft, then split into two drops into first floor rooms and ground floor rooms directly beneath, then along length of house before returning back to boiler.

get a heating engineer in to give you some advice. explain you may wish to carry out the pipework etc yourself but you would be prepared to pay a consultancy fee for his expert knowledge and opinions.

Thanks for the suggestion. That sounds like a good approach.

heat losses on any long uninsulated pipe runs aren t helping the efficiency of the system , especially under the floor.

edit - is your existing boiler room sealed or open flued ?

Conventional flue straight up and out through the roof of the lean-to.

 

[noleaksihope]

afraid it may be time for a new boiler and re pipe if you want to make decent energy savings niall . not sure if the oil savings are the same as on gas appliances , replacing a gas open flue with a condenser you d save 20-30%. wouldn t reccomend replacing a fan flued room sealed in good working order with a condenser , only going to save 10-15%. way oil and gas prices are rising though , 10-15% will add up over the years .

used to see 1 pipe systems in schools , hospitals , churches etc with big old cast iron rads . not suited to steel panel rads on poorly designed systems.

get an oftec engineer in to give you an idea on cost of replacing the boiler , sure he wont mind giving you some pointers on tackling the pipework to the rads if hes there replacing the boiler.

ideal job for the summer , rip it all out first and use some of the old runs for the new pipework.

 

[niallcook]

afraid it may be time for a new boiler and re pipe if you want to make decent energy savings niall . not sure if the oil savings are the same as on gas appliances , replacing a gas open flue with a condenser you d save 20-30%. wouldn t reccomend replacing a fan flued room sealed in good working order with a condenser , only going to save 10-15%. way oil and gas prices are rising though , 10-15% will add up over the years .

used to see 1 pipe systems in schools , hospitals , churches etc with big old cast iron rads . not suited to steel panel rads on poorly designed systems.

get an oftec engineer in to give you an idea on cost of replacing the boiler , sure he wont mind giving you some pointers on tackling the pipework to the rads if hes there replacing the boiler.

ideal job for the summer , rip it all out first and use some of the old runs for the new pipework.

Thanks again. What's the logic behind replacing the boiler? It's a Grant 90-120 Euroflame boiler room model. From the commissioning label, it was only installed in 2005. Sounds like a pretty poor return if it needs chucking out after just 5-6 years service.

 

[noleaksihope]

Thanks again. What's the logic behind replacing the boiler? It's a Grant 90-120 Euroflame boiler room model. From the commissioning label, it was only installed in 2005. Sounds like a pretty poor return if it needs chucking out after just 5-6 years service.

to reduce the oil consumption while still providing the same heat output with a more efficient boiler .

not clued up on the efficiency savings to be with oil, your boilers not that old niall . you can probably get the SAP rating for it in the install manual or online and compare to newer models. when replacing an older conventional flue gas boiler with a condenser, gas savings are usually 20-30%, some customers have reported +40%, but they re also probably lowering the room & trvs , heating less hot water with a combi rather than a full cylinder just to do the dishes etc

annual gas bill of £1000 , 20-30% savings is £200-300 per year , £1000-1500 over 5 years , new boiler comes with full parts and labour 5 year guarantee, it s paid for itself in the 5 year guarantee period is the logic while reducing your carbon footprint.

any idea of your annual bill for oil ?

 

[niallcook]

to reduce the oil consumption while still providing the same heat output with a more efficient boiler .

not clued up on the efficiency savings to be with oil, your boilers not that old niall . you can probably get the SAP rating for it in the install manual or online and compare to newer models. when replacing an older conventional flue gas boiler with a condenser, gas savings are usually 20-30%, some customers have reported +40%, but they re also probably lowering the room & trvs , heating less hot water with a combi rather than a full cylinder just to do the dishes etc

annual gas bill of £1000 , 20-30% savings is £200-300 per year , £1000-1500 over 5 years , new boiler comes with full parts and labour 5 year guarantee, it s paid for itself in the 5 year guarantee period is the logic while reducing your carbon footprint.

any idea of your annual bill for oil ?

A lot! But then it's a big house (two houses actually) with two boilers and an Aga. No gas in the village. SAP rating for current boiler is C. One website I looked at said unlikely to get any significant efficiency savings from replacing with a new A rated oil boiler.

Appreciate there may be savings to be had with gas, but that's not an option for us.

I'm assuming that there would be little point replacing the boiler without converting to a two-pipe system as well.

 

[dwb78]

1 pipe system matey rip it all out ta ***, get something nice in there. oils to bloody dear

 

[niallcook]

1 pipe system matey rip it all out ta ***, get something nice in there. oils to bloody dear

Agree with that. Problem is that ripping it all out isn't going to be the cheapest option in the world either. Spend £6k plus and still have to buy the oil. Payback's going to be at least 5 years I would think.

 

[franky]

If the boilers 6 years old keep it but the one pipe system seems like your main concern so change this look at saving to be made with thermostatic rad valves. But if you want to make big savings insulation is the way to go, trap the heat in your house.

 

[stani]

as you say your boiler is a large oil, that uses around 3.1 litres/hour if you have the boiler on 2 hours in the morning and 3 hours at night thats 15.5l/hr 10days = 155 litres 30 days 465 litres you can easily go through a 1000 litres in 2 months more if its particularly cold. best thing is get rid of single pipe system then use zone valves to heat only areas that you are using, the grants a good boiler dont throw it away. No matter what boiler you put on a 1 pipe, none will be efficient.