Should I convert a one pipe system to a two pipe system?
- Thread starter DJS1
- Start date
Sponsored Links
Yes, if you're upgrading the system you could consider, a 3port valve and a fully pumped system.
Don't add the inhibitor until you have tested the work.
Don't know where you are but PTS in Frome is a good outlet for fitting etc.
My weekend will be partying and making merry, followed by a 200 mile drive home Sunday night.
Don't add the inhibitor until you have tested the work.
Don't know where you are but PTS in Frome is a good outlet for fitting etc.
My weekend will be partying and making merry, followed by a 200 mile drive home Sunday night.
My weekend will be partying and making merry, followed by a 200 mile drive home Sunday night.
200 mile drive sunday night
Don't you have a cooker?
My weekend will be partying and making merry, followed by a 200 mile drive home Sunday night.
200 mile drive sunday night
Don't you have a cooker?
And a 200 mile drive to get there Saturday morning.
Yes I have a cooker, but not the company.
Sponsored Links
evening boys
WOOF WOOF!!!!!!
WOOF WOOF!!!!!!
I had a similar dilemma to you, so I hope my experience may help. I bought a 1960's detached house that originally was heated by solid fuel (converted to gas later when the gas supply arrived) so I inherited the 15mm one pipe radiator system with 7 radiators. The first winter it was impossible to control the temperature. The upstairs rooms were too hot, the downstairs too cool, and the hot water scalding, so I set about improving it.
I intended to upgrade in stages, so I got rid of the old primatic hot water cylinder, converted it to fully pumped (S Plan) with a roomstat in the hallway and added TRV's. I fitted standard Pegler Terrier TRV's not realising that there are special one's for one pipe systems but they work fine. That took me to the second winter, so I was going to upgrade the "one pipe" to "two pipe" the following summer. That was 11 years ago, but it's still there.
It works perfectly, we never have to adjust the thermostat /TRV settings regardless of the outside temperature, and surprisingly our bills are less than our neighbours (I know that there are lots of factors to be taken into account here). However I have discovered other benefits to me.
1. No by-pass needed, the loop of the one pipe circuit offers a free flow of water at all time even if most rads are closed due to their TRV's.
2. The original downstairs oak floor remains in tact.
3. The system is silent, there is no pump noise or "hiss" associated with water under pressure passing through a partially open TRV. This is because most of the water flows around the one pipe loop and circulates gently through the radiators rather than under pressure.
4. Having less pipework, the system contains less water, so it soon heats up. (The corrosion inhibitor is less diluted too)
5. No balancing issues. All lockshield valves are fully open as the same water flow passes all radiators. It's true that to start with, the last radiators in the circuit are slightly cooler to the touch than the others, however they soon warm up as the TRV's on the other radiators shut down.
6. The one pipe system is aided by gravity, so the pump is only set to a low speed, nice and quiet and saving electricity. As the pump doesn't have to work so hard, maybe it will last longer.
Are there negatives, I'm sure there are. My boiler is not a condensing variety. I read somewhere that condensers are not as efficient with a one pipe system, something to do with the return water temperature being higher, I believe. The radiators at the end of the circuit are not quite as hot as the others, but this doesn't really cause a problem the rooms get warm and that's really what matters.
For me at the moment I've left it well alone, it works well, isn't expensive to run and has been trouble free for 11 years. I can't imagine a return on the investment to change it to 2 pipe in terms of financial savings or comfort.
I intended to upgrade in stages, so I got rid of the old primatic hot water cylinder, converted it to fully pumped (S Plan) with a roomstat in the hallway and added TRV's. I fitted standard Pegler Terrier TRV's not realising that there are special one's for one pipe systems but they work fine. That took me to the second winter, so I was going to upgrade the "one pipe" to "two pipe" the following summer. That was 11 years ago, but it's still there.
It works perfectly, we never have to adjust the thermostat /TRV settings regardless of the outside temperature, and surprisingly our bills are less than our neighbours (I know that there are lots of factors to be taken into account here). However I have discovered other benefits to me.
1. No by-pass needed, the loop of the one pipe circuit offers a free flow of water at all time even if most rads are closed due to their TRV's.
2. The original downstairs oak floor remains in tact.
3. The system is silent, there is no pump noise or "hiss" associated with water under pressure passing through a partially open TRV. This is because most of the water flows around the one pipe loop and circulates gently through the radiators rather than under pressure.
4. Having less pipework, the system contains less water, so it soon heats up. (The corrosion inhibitor is less diluted too)
5. No balancing issues. All lockshield valves are fully open as the same water flow passes all radiators. It's true that to start with, the last radiators in the circuit are slightly cooler to the touch than the others, however they soon warm up as the TRV's on the other radiators shut down.
6. The one pipe system is aided by gravity, so the pump is only set to a low speed, nice and quiet and saving electricity. As the pump doesn't have to work so hard, maybe it will last longer.
Are there negatives, I'm sure there are. My boiler is not a condensing variety. I read somewhere that condensers are not as efficient with a one pipe system, something to do with the return water temperature being higher, I believe. The radiators at the end of the circuit are not quite as hot as the others, but this doesn't really cause a problem the rooms get warm and that's really what matters.
For me at the moment I've left it well alone, it works well, isn't expensive to run and has been trouble free for 11 years. I can't imagine a return on the investment to change it to 2 pipe in terms of financial savings or comfort.
Thanks for your reply Stem, always good to hear of other's experiences and you make an interesting point about volume of water.
Once I've resolved the pressure drop problem I mention in my other post, then cleaned out the radiators, I'll be in a better position to decide what to do.
My position is slightly different to yours in that I've got a condensing boiler (maybe this makes no difference) but more importantly three downstairs radiators don't get very hot.
I'm tempted to get on and make the change, but the other half would rather I got on and finish the loft conversion!
Once I've resolved the pressure drop problem I mention in my other post, then cleaned out the radiators, I'll be in a better position to decide what to do.
My position is slightly different to yours in that I've got a condensing boiler (maybe this makes no difference) but more importantly three downstairs radiators don't get very hot.
I'm tempted to get on and make the change, but the other half would rather I got on and finish the loft conversion!
I'm now under way converting my CH to a two pipe set up and I'm hoping somebody can help me with the pipe layout.
My plan was to branch the flow and return pipes off as soon as practical after leaving the boiler, one to feed one upstairs radiator plus the down stairs and one to feed the rest of the upstairs.
However, the layout of the house means it would be easier to branch off slightly further on which would leave one upstairs radiator and one downstairs radiator on a small loop of their own.
Would this small loop cause problems with the two radiators getting too much heat or will balancing be able to prevent this?
I'm not after perfection and this solution allows me to avoid going through an old external wall.
Thanks for your comments.
My plan was to branch the flow and return pipes off as soon as practical after leaving the boiler, one to feed one upstairs radiator plus the down stairs and one to feed the rest of the upstairs.
However, the layout of the house means it would be easier to branch off slightly further on which would leave one upstairs radiator and one downstairs radiator on a small loop of their own.
Would this small loop cause problems with the two radiators getting too much heat or will balancing be able to prevent this?
I'm not after perfection and this solution allows me to avoid going through an old external wall.
Thanks for your comments.
DIYnot Local
Staff member
If you need to find a tradesperson to get your job done, please try our local search below, or if you are doing it yourself you can find suppliers local to you.
Select the supplier or trade you require, enter your location to begin your search.
Are you a trade or supplier? You can create your listing free at DIYnot Local
Sponsored Links
