Boiler/Heating setup.. Total rethink.

[westfire32]

As you may have seen from some of my other postings, I am looking at the layout/operation of a heating system installed at my daughters new home, which at one time had been two older houses.

Over the weekend I have had the opportunity to make a more detailed observation of the layout of pipework, etc, and can see that the property (and heating system) has suffered from having additions and alterations carried out in various stages, and is, in my opinion, overdue an overhaul.

Basically there are 2 combi boilers which feed into a common flow return. This common/return feeds all radiators in the house, and there is also a branch which feeds to TWO megaflo tanks in the loft (55 gallons each), feeding hot water to a bath and a shower.(not sinks).

This is all controlled by a single "very basic controller,(heating/water or water only)." , and a room thermostat. When the heating is on so is the hot water (no thermostatic/motorised valve control)

I am considering changing the system around to provide the following configuration

Boiler 1 to provide heating to ground floor
Boiler 2 to provide heating to first floor and say heat megaflos.
(or vice versa)
The intention being to Zone the heating, make the water heating more efficient AND ultimately save money on energy costs.

Believe it or not but there would be very little pipework reconfiguration necessary to make this change, and the main additions would be 2 good quality timeswitch/thermostat controllers, motorised valve and reconfiguring the wiring.

I am very confident in making the necessary changes, however I would welcome opinions on my idea,
OR any other suggesttions.

Comments please... TWO MEGAFLO 55Gallon tanks.. is this an overkill??

 

[Meldrew's mate]

...no thermostatic/motorised valve control...
...TWO MEGAFLO 55Gallon tanks.. is this an overkill??

might be a case of manslaugter (is daughterslaugter a word?) if you dont fit the mandatory (and supplied) zone valve to each megaflow.
55 gallon is about 250 litre. Normal sizes are 210 and 300 litre megaflow, both of which are large enough on their own
Your use of imperial sizes makes me tend to question your information, as Megaflows are clearly marked with their sizes only in litres

If one combi isn't big enough, and most are >24kW, then use one for the upper floors and Megaflow, second for downstairs only and kitchen DHW. If you can ditch one of the boilers just add zone valves for each floor, and one for the ONE Megaflow. Sell the second on Ebay!! Having one boiler will reduce running costs considerably.

Hope this helps

MM

 

[westfire32]

Thanks for the info.

The model number on the megaflo is CL250, and the imperial measure is my approximation (still work in pounds, shillings, and pence).

At the moment the megaflo's are connected in parallel, and whilst I would like to try isolating one, and running the other (to test the capacity) I am very wary of shutting off flow/return and feed/outlet, to one megaflo.

Any thoughts on this?

With regards to your comments on the Boiler output being sufficient to run the system, as both boilers seem to be 5 to 6 yrs old, it may be better to run one and keep one in reserve. In fact it will be very easy to check if one boiler is sufficient by simply isolating the flow/return via the online wheel valves, isolating power, and gas supply. Thanks for that tip.

 

[bengasman]

Unless someone in the family is really good at this, the only real solution is to get a proper installer to sort it out. There will be a variety of issues that cause never ending problems, nuisance and cost.

 

[Agile]

Ben, I think you will find that this is a retired builder!

As we all know, builders think that they know everything about plumbing and gas work!

Until it all goes wrong that is!

They are also very unreliable at paying too.

I only now do work for builders who will pay up front with hard cash. In reality thats no builders of course.

Tony



PS The exception is the builder in Reading who has no problem paying! He gets a wonderful speedy 4 hour service from me.

 

[bengasman]

What a coincidence, I do not work for builders either. Or for anyone who knows a lot about boilers. Obviously we can only rip off people who are ignorant

 

[westfire32]

Thanks Guys.

Firstly I am not a retired builder, I owned a company that employed 25 specialist tradesmen (not in the plumbing trade), and we prided ourselves on paying our bills on time.

I asked questions on the forum, seeking sensible advice mainly to confirm (from specialists) what i was already thinking.

If you wish to throw snide remarks at people who are genuinely interested in doing things correctly, then so be it. (but it doesn't do your credibilty any good)

Incidentally, just by way of illustrating peanuts & monkeys, this property is fitted with Bisque radiators (costing approx £700 each) specified by the previous owner I hasten to add, and the quality of workmanship by the expert installer was CRAP (should you wish I could forward some nightmare pipework layouts.)

I appreciate the advice that I have been given up to now, and would very respectfully ask for advice only....snide comments.. no thanks.

 

[westfire32]

Oh and just as a footnote.

Perhaps you wonder why I am doing this work myself, when either my daughter or myself could easily afford to pay for it to be done.

Mainly because I have plenty of time on my hands, to both research a problem, and coupled with past experience, the ability to do things correctly.

My time doesn't cost any money..

 

[Agile]

I think that I recommended that you checked and probably increased the temperature of the boiler output that heated the cylinder.

Did you do that and what did you find?

Be aware that you seem hell bent on making changes which we ( well most of us ) would not recommend.

Tony

 

[westfire32]

Thanks Tony.

Yes I did, and actually got some more air out of the Megaflo flow/return loop.

Megaflo's are heating better now.

I do appreciate your "warning" (meant in the nicest possible way), but honestly, if you could see the pipework layout, and the absolute CRAP standard of workmanship on this installation, I think you would be horrified, and this work was done by qualified people.(experts).

As an example, the hot water outlet from the megaflo (22mm) which obviously comes from the top of the tank, could very easily be shortened by 3 metres, and have 3 manufactured bends taken out, making it a straight run. there is no logic whatsoever to some of things which have been done on this installation.

As you will see from my questioning, I am also looking to increase the efficiency on the complete system. the temperature/timing configuration is almost none existant

I may very well take some photographs and set up a "chamber of Horrors"

 

[Agile]

You have two cylinders but question removing one of them.

My advice is to keep them both unless you are convinced a single one would be totally sufficient. I dont see anyone putting in two unless they thought they were both required.

They are VERY well insulated and there is minimal heat loss. The pipes should be insulated though.

You can seperate the boilers if you have to but I would in my own home keep both as a main and a peak loping and fit heating zone valves and controls as required.

Tony

 

[Onetap]

Basically there are 2 combi boilers which feed into a common flow return.........


Comments please... TWO MEGAFLO 55Gallon tanks.. is this an overkill??

Are you sure they're combi boilers?
Combis generate instant hot water with an internal heat exchanger, so their main advantage is that there's no requirement for any hot water storage cylinders. What make/model are they?

 

[Balenza]

westfire32 wrote

and have 3 manufactured bends taken out

That will be the cc's. (corgi cowboys). Their hell bent on using fittings.
Can you a post picture of the offending pipework please.

 

[westfire32]

reply to "one tap".

Absolutely certain beyond any shadow of doubt that they are combi's.
Yes I know about the "instant" hot water aspect, which both of these have, I also know that the flow/return from the heating side also feeds circulation into the Megaflos.

reply to Balenza.

I am 80 miles away from the installation in question, next time I visit my daughter, I think I will take a complete "roques Gallery" of pics. As I feel some folk don't believe what I am saying.

Guys please believe me. This system is a cockup..