Curiosity about system

[Carlos_UK]

Hiya,

I've been nagging at my mum to upgrade her boiler to a more efficient system, as she currently has a Baxi back boiler which was installed easily 20 years ago and has pumped central heating and gravity fed hot water.

Now what has made me curious is to how this system works in relation to controls, I understand what the function of the 2 tanks in the loft are and the room stat, but the cylinder has no stat on it and there are no valves, so does this mean that the boiler has separate flow and return pipes for DHW and heating, and with no cylinder stat, does this mean the boiler is running constantly when the hot water is on as it has no way of telling when it has reached the correct temperature?

Carl.

 

[Centralheatking]

I would leave well alone - the system works and any new boiler would have to be somewhere
else and cause disruption. If you are going to muck about do it next summer. CHK

 

[Carlos_UK]

I would leave well alone - the system works and any new boiler would have to be somewhere
else and cause disruption. If you are going to muck about do it next summer. CHK

Hi Centralheatking,

I do not intend to or would never do anything to it as I'm not a plumber, but am just curious as to how the current system works!

Carl.

 

[jtsplumbing]

Hot water is controlled by timer / temperature by what the boiler thermostat is set at,

 

[julesverne]

i would definetley leave this kind of job till the spring i have 2 back boilers conversions booked in for elderly couples that are going to be done in spring.

 

[Carlos_UK]

i would definetley leave this kind of job till the spring i have 2 back boilers conversions booked in for elderly couples that are going to be done in spring.

My Mum has no intention of getting it replaced until it packs up, its just something I keep saying she should consider getting done at some point, and was just curious as a side note as to how it works, I suppose in relation to my Y plan system!

 

[kay-jay]

well now you know!
your y-plan system will be a fully pumped system with the pump sited downstream from the valve so the hw gets pumped too. your boiler will have just one flow and return which separates at the motorised valve on demand.

 

[Carlos_UK]

Thanks a lot everyone, that's something else I've learnt about system layouts!

So the system as it stands, does have pretty much the same controls as a more modern system, apart from not being able to have the central heating on without hot water as well?

 

[doitmyself]

does this mean that the boiler has separate flow and return pipes for DHW and heating

The flow pipe will be separate, but the return can be separate or common, depending on the boiler.

with no cylinder stat, does this mean the boiler is running constantly when the hot water is on as it has no way of telling when it has reached the correct temperature?

The hot water temperature is controlled by the boiler thermostat, which is why you turn the boiler stat down in the summer to about 65C. In the winter, the boiler temp is turned up so the rads get hot enough, which means the hot water can get too hot.

 

[Carlos_UK]

Thanks ever so much!

 

[Howsie]

And now off to try it myself...

 

[Centralheatking]

You could help your relative by insulating the place as much as poss - fancy controls and boilers are all ok but insulation is easy and best !st step CHK - i took you to be a new youg fitter wanting to experiment with your relatives hse sorry QUOTE=Carlos_UK;577301]Hi Centralheatking,

I do not intend to or would never do anything to it as I'm not a plumber, but am just curious as to how the current system works!

Carl.[/QUOTE]

 

[Carlos_UK]

No worries Chk, I was just interested in how the system works as I couldn't quite picture it in my mind, and I'm one of those people who has to understand how things work!

She's already got foam loft insulation, but the house always seems cold (a lot colder than I remember it being growing up) and when touching the rads, they don't feel hot enough to me, but are warm all over, she also has an air brick in the living room which makes it freezing cold but is apparently required for the boiler.