Please help me understand my problem and what I can do about it!!

[Dan Robinson]

 

[bernardgreen]

Transposing one set of disadvantages for another without explaining.

So please explain to me and others what are the disadvantages of a vented cylinder and passive heat exchangers. ( passive meaning does not need a pump to circulates water from heat store through the heat exchanger. I looked at the informal notes about installation of the plate heat exchanger ( Type LA 14 TL AA 20 if you want to comment about it ) ""Pipe work should be arranged to allow easy isolation and removal of the exchanger for de-scaling""

You try to avoid giving facts prefering to use words like foolish to try and discredit people whose opinions are different from yours.

Please do not repeat the dead mouse in cold water tank scenario, it may happen if there is no cover on the tank but the results of inadequate servicing of a un-vented cylinder can be more serious.

 

[Dan Robinson]

So you want to limit the scope of an argument to your own parameters? I could trawl through a load of manuals and post up text where the plate defends itself against scale, btu I have too much paper work to do and have to go to Heathrow this afternoon. You can do your own googling.

Passive heat exchangers are fine.... when designed and installed correctly... but how many of us with an experience greater than 1 poxy cottage have had Boilermates scaled up so badly that they just trickle? hhhm....

Thermal store type systems have advantages, but they are no more compact than regular cylinders in fact, they often need to be bigger.

And before you go off on another tangent... I have had a 300 litre thermal store (plate HEX based) in this house. Took it out for a 150 litre unvented cylinder. You can buy the store off me if you like.

 

[bernardgreen]

but how many of us with an experience greater than 1 poxy cottage

Why put the word "poxy" into the sentence ? Degrading the person rather than the opinion ?

Excuse my ego trip but this is the Walter Segal designed house that my wife and I self built in 1980 / 81

so my experience on designing heating and hot water systems in not limited to one Grade II listed thatched cottage. There is also a considerable amout of experience in the control and monitoring on industrial heating and hot water systems.

 

[muggles]

but how many of us with an experience greater than 1 poxy cottage

Why put the word "poxy" into the sentence ? Degrading the person rather than the opinion ?

Excuse my ego trip but this is the Walter Segal designed house that my wife and I self built in 1980 / 81
View attachment 96651
so my experience on designing heating and hot water systems in not limited to one Grade II listed thatched cottage. There is also a considerable amout of experience in the control and monitoring on industrial heating and hot water systems.

Very nice, now that you've inflated your ego a bit would you mind if we got back to the actual topic, rather than dragging yet another conversation towards your slightly dodgy opinions?

 

[Dan Robinson]

Why put the word "poxy" into the sentence ?

Pure frustration.

 

[Phil12345]

Bernard - I'm sorry if I sound rude but I don't care about any issues or grudges you have, take them on your own thread. I'm trying to learn something off these boys and your issues aren't helping.

Cheers

 

[Dan Robinson]

I should add that in my two vids are running off a 15mm incoming main.

 

[Phil12345]

For those recommending the unvented, is the new 22mm pipe likely to take my flow up to te minimum 20l/min required?

I guess te question is what flow and pressure is comin in the blue mdpe pipe before the 15mm main takes over.

I just wanted to lose the cylinder but doesn't look like I can does it?

 

[Dan Robinson]

You can lose the cylinder's and have a hugely over powered combi. It will not be as efficient as it should be though.

Upgrading the pipe should give you decent enough performance. I have 3 bar working pressure on 25mm mdpe and 22mm throughout.

I can fill my bath in 5 to 8 minutes depending on depth.

 

[Phil12345]

Plate heat exchangers - if specced correctly, will flex and break off the scale. Unless in a crazy hard water area in which case treatment should be in place anyway.

Having two water supplies will do nothing for the pressure. It will increase the flow rate.


I do agree with Bernard that combi's are a nightmare in these situations, although Vokera and Viessmann are making great strides in Turndown ratios. However they are a compromise. My default solution on this system (as described) would be a 180 litre unvented cylinder sitting under a 15kW or 18kW system boiler on hot water priority.

The 15mm copper should be changed for 22mm all the way to the cylinder location and the cold for the house drawn off the balanced outlet of the cylinder control group. If the upgraded pipe is not going to work, replace the cold water cistern with the aforementioned accumulator and then put an unvented cylinder in. Maintenance would add an hour per year, but an engineer with G3 unvented is hardly going to cost anymore than one with Gas Safe registration. Christ, it only takes 15 minutes to renew the certification when taken with the other exams.

Of course you can keep your cisterns in the loft and have noisy mechanical pumps.

Cheers dan. It's funny because your solution here is the only one I've been recommended twice!!

In your vids is the message that I will more than likely need an accumulator? And when you say an unvented "under" a 15kw or 18kw, is that just a figure of speech or do you mean under as in physically below?

I guess we'd keep the same boiler in this situation

 

[Phil12345]

One more thing! In your default solution how much would you add price wise for te necessary accumulator add?

 

[Dan Robinson]

Price very much depends on configuration... One big one, or several small ones.

I was referring to physical location but assuming an airing cupboard fit with accumulators in the loft.

 

[Aquaheat]

edited as dan beat me to it

 

[bobdogavitch]

How about a powerful combi that can be range rated? I'd have thought the cheapest option.