pumped dia 
Adding resistance to a DHW circuit?
- Thread starter DIYedboy
- Start date
So are we talking about the Suprima with 2 x 2 port valves, but no cylinder stat to turn one of them on/off
looks that way
Apologies for the confusion I've caused you lads, MY system is pumped HW and CH, stat on tank 2no 2 port valves, the cylinder is about 10yrs old.
Perhaps (on reflection) I'm just being a total nob, if my system don't have a restrictor on the HW circuit at the moment what is the need to fit one? after all when the cylinder temp is reached, the stat will tell the zone valve to close and then the water will have to flow round the CH circuit!
Or yet again am I wrong?
Perhaps (on reflection) I'm just being a total nob, if my system don't have a restrictor on the HW circuit at the moment what is the need to fit one? after all when the cylinder temp is reached, the stat will tell the zone valve to close and then the water will have to flow round the CH circuit!
Or yet again am I wrong?
If you dont fit a regulating valve then the coil output will return at the same temperature and encourage the boiler to shut down sooner. The boiler has an anticycle delay for 2-3 minutes and during that time there wil be no heating.
Its a bit more complicated than that though as your boiler does not modulate like modern ones and restricting the flow can cause it to turn off sooner!
The other and usually main need for it is to stop the cylinder hogging all the flow when HW and CH are on together.
There are many problems posted here which are caused by having no regulator on the HW and its surprising why so many professionals dont realise the need for them.
With the HW only on I would set the flow on a cold cylinder to give a differential of about 10 degrees.
Tony
Its a bit more complicated than that though as your boiler does not modulate like modern ones and restricting the flow can cause it to turn off sooner!
The other and usually main need for it is to stop the cylinder hogging all the flow when HW and CH are on together.
There are many problems posted here which are caused by having no regulator on the HW and its surprising why so many professionals dont realise the need for them.
With the HW only on I would set the flow on a cold cylinder to give a differential of about 10 degrees.
Tony
Great, good man Agile, should I use a Pegler fullbore 22mm ball valve as my 'restrictor' as it appears they work better?
Secondly, when testing the 10degree drop, should I do this with the cylinder cold but the boiler hot or both cold?
Secondly, when testing the 10degree drop, should I do this with the cylinder cold but the boiler hot or both cold?
like 2 pages back 
and alright the pic wasn't a lockshield
and alright the pic wasn't a lockshield
like 2 pages back
and alright the pic wasn't a lockshield
Tis if you take the andle orf.
I would use the gatevalve as so much cheaper and they do the job.
Start with the valve closed and open it JUST one turn then measure the temperatures with the cylinder cold and the boiler hot ( obviously! ).
Its actually pretty easy to guess the temperature as there should be a noticeable hand felt difference between the two but a real measurement is better if you can.
I teach trainees to measure temperatures with their hands so they can do a quick assessment without instruments. Its surprising how accurate you can be with hot water. They assess the temp first and then we measure it!
Its always useful to know how to get by incase you are ever called to repair something without tools. Like the time I was having a meal out with some friends and BG had left the restaurant without any central heating in January. A quick poke to the Vaillant fan and it was working for the next 25 min!
Tony
Start with the valve closed and open it JUST one turn then measure the temperatures with the cylinder cold and the boiler hot ( obviously! ).
Its actually pretty easy to guess the temperature as there should be a noticeable hand felt difference between the two but a real measurement is better if you can.
I teach trainees to measure temperatures with their hands so they can do a quick assessment without instruments. Its surprising how accurate you can be with hot water. They assess the temp first and then we measure it!
Its always useful to know how to get by incase you are ever called to repair something without tools. Like the time I was having a meal out with some friends and BG had left the restaurant without any central heating in January. A quick poke to the Vaillant fan and it was working for the next 25 min!
Tony
Ahhhh Kev, I shall take that poke with a resigned and deserved acceptance! 
Onetap suggested that they weren't much good, so I thought I'd move into the 21st centuary with a sexy old pegler job, however, it would appear that the humble gatevalve is still the tool of choice! and it is not for me as a mere fiddler to question those that have the knowledge, so a gatevave it will be.
Agile, many thanks for 'wet nusing' me through the restriction setting process, your ability to teach shines through,I look forward to ripping out my system and playing with me valve!
Onetap suggested that they weren't much good, so I thought I'd move into the 21st centuary with a sexy old pegler job, however, it would appear that the humble gatevalve is still the tool of choice! and it is not for me as a mere fiddler to question those that have the knowledge, so a gatevave it will be.Agile, many thanks for 'wet nusing' me through the restriction setting process, your ability to teach shines through,I look forward to ripping out my system and playing with me valve!
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