Help with dhw output please

[lolly]

Hi,
Please can somebody help me understand the output of these 2 combis.
I have a choice of Main eco 30he and Potterton Gold 33he.
I know that the 30kw boiler is enough for my 3 bed bungalow, but am worried about the water performance during the winter months for bath filling etc. due to mains temperature being colder.
Would i be right in assuming that the 33kw would give an improvement, if so, would there be much difference over the 30kw?Would the 33 deliver the dhw quicker? Hope i am making sense.
I have been looking at both specs and cannot really understand fully.
I am getting over 14 to 14.5 litres pm at the moment from kitchen tap, so can fully support either combi (i think!).
Would there be a great deal of difference as well in the gas usage?
I dont want to go for the lower one and not be happy, and the same with the other, dont want to ;overkill; without any benefit.
I think my heating load is only small so that doesnt matter (i think).
Thanks very much, any help much appreciated....

 

[Billy Bob Bob]

not much in it main 31 input poterton 33 input how many dhw outlets are you running not many combis will do both taps going and you need good mains presure on a reliability front the main 30 he aco is unproven,better off with a main 30he.its a baxi 105 in disguise,also the 33kw potterton is a baxi platinum/duotec in disguise another reliable combi if it was me it would be the main 30he[not aco] this bangs out the hot water also potterton performa 30he is the same macine

 

[lolly]

Hi,
Thanks. Just one bathroom,so looks like a 30 would be enough then. It must be an A rated due to the scrappage though. Will look at the others you quoted .
My trouble is i have done too much homework and baffled myself with all this info. I was worried about the colder winter months and the water delivery due to the temp changes. Just dont want to make a mistake, Ta.

 

[Billy Bob Bob]

if its a rated duotecor plat or potterton gold or promax not to confuse you these are all the same boiler but warrenty periods differ the platinum 5 years gold 3 years duotec and promax 2 years but it costs a lot more for a plat over say a pot gold

 

[lolly]

Hi,
No, those boilers are all Band B. I was drawn to the Potterton Gold as it has the stainless steel HE and good warranty, whereas the Main 'eco' only has 1 year, although i hear very good reports about them. The price difference between the 2 isnt too much either. Hmmmm....so confusing...

 

[Billy Bob Bob]

the gold is a band a 3 year warranty that sounds like the best value

 

[lolly]

Thanks. They have just changed the warranty on the Gold to 2 years for some reason, but i can source a last years model which will still have the 3 years warranty. I think this is why i am attracted to the '33', but the rgi who came to price said all i need is 30kw, but if the flow rate is higher on the '33' isnt it the 'better' choice? I take it the heating load modulates down to what i need anyway?
I could take his advice and go with the Main Eco, but it could end up costing more in the end due to just a one year warranty and not much cheaper to buy than the 'gold'.
Is that logical thinking (for a woman..hehehhee) The whole process is driving me 'nuts', lol!

 

[Billy Bob Bob]

Thanks. They have just changed the warranty on the Gold to 2 years for some reason, but i can source a last years model which will still have the 3 years warranty. I think this is why i am attracted to the '33', but the rgi who came to price said all i need is 30kw, but if the flow rate is higher on the '33' isnt it the 'better' choice? I take it the heating load modulates down to what i need anyway?
I could take his advice and go with the Main Eco, but it could end up costing more in the end due to just a one year warranty and not much cheaper to buy than the 'gold'.
Is that logical thinking (for a woman..hehehhee) The whole process is driving me 'nuts', lol!

go for the gold,your right it will modulate down for ch and if dhw is to hot just turn the stat down on the boiler [it has one forch and one for dhw] i did a course on the main 30aco he and was not inpressed [bearing in mind i repair boilers for a living] and dont like unreliable boilers as i insure lots of my own installs

 

[lolly]

Thanks, you have been a great help, i was just frightened that i was buying something too big, but someone told me a long time ago, if i were to change to combi to go for a 35kw for hw delivery. My hubby likes a bath and from what i have read, during the colder winters we are having, that the performance of the water is affected because of the incoming colder water. I think i am making sense of it all, LOL, i reckon i could be on a course, i am 'learning' wuite a bit. I just dont like the idea of spending out quite a bit and 'getting' it wrong. Its worth doing all the research. I started off looking at the Broag, lol, parts are extortionate, so decided to head for 'middle' range budget. At least with the warranty, at least if i get the'friday' boiler i am at least covered for quite a while. The scrappage allowance will help as well.

 

[Billy Bob Bob]

go with the gold or duotec you wont be disappointed

 

[lolly]

Hi,
Sorry to be a nuisance, but i am now comparing the gold 33 he with vaillant ecotec plus 831. What are the differences between these boilers on the hw performance?Is the Gold one more powerful. Which would be the better boiler? I am just worried about the reports on Vaillant aftercare should i need it.I am not bothered about the preheat on the water much cos that just burns more gas from what i have researched.
The Gold seems quite a bit cheaper, is there anything else different? They bpth seem to have stainless steel heat exchangers. Bearing in mind i dont have to look at it as it will be installed in the garage.
Many Thanks

 

[Billy Bob Bob]

the gold is just as reliable as the vailent,but spares are cheaper and its easier to work on,hot water performance wise its more powerfull

 

[lolly]

Hi,
Thanks for that infor, i am leaning more towards the Gold, makes me happy to know they are equally reliable.
Just one more think with the Gold, do you know how far it modulates down to for the heating, i cannot find out anything about that.
I think the Vaillant modulates down quite low. Just worrying about the running costs overall to make the final decision.

I have spent more time researching this combi than anything else i have ever bought, LOL, every time hubby comes home from work he says 'what make combi are we buying today!'
Needless to say i am getting 'very' close, at long last....

 

[Billy Bob Bob]

it will modulate down to whatever load the system is if the systems 18kw it will match its output accordingly basicly all combis run to high rate untill the ntc[thermistor]senses the return temperature and tells the pcb to turn the gas rate down most combis will go down to 4 mb automatically regardless of make clever stuff modulation

 

[lolly]

Hi Gasman,
Thanks for your reply, was just double checking, lol, my fitter will be so impressed with my jargon....not!!
I have learnt so much from the forums, and at least found out the bits i should have fitted, these could get so easily overlooked if the wrong person comes to your house to price the install.
It seems to have paid me to do the necessary homework, and have a clearer understanding of what and how it all works...
Thanks again, your info and input much,much appreciated, i feel a whole lot happier about everything as i do panic when it comes to major stuff in the house, lol!
Cheers

Hi Again,
Right, now for my next dilemma! After reading many articles about people saying you should keep your old boiler, i am wondering now. I just assumed my boiler is knackered cos of all the hype with the scrappage scheme. I have had a leak on one of the pipes to the boiler for some 6 years and just put a bucket under it. It is literally a drip. One of the rgi's that came last week said that years ago when i had someone look at it, they probably said it couldnt be repaired cos the pipe backs onto the garage wall and hard to fix it...hmmm...it is some sort of release valave i think. The guy before took a little piece out and left it.
Now the boiler is an Ideal Stelrad wlx rs60 and works fine, but in need of a service. Is it possible we could get some more years out of it rather than replace. Should there be any parts that could need replacing? In 24 years it has only had a thermocoule thingmy and i think thats about it!
Are the parts if needed available? Would it pay to get another rgi to look at the boiler before deciding to take the plunge over to a combi. I was thinking we could pay to have the system properly cleaned and the leak fixed. What are your thoughts? Is this being wise, as i said the boiler works fine and is reliable....
Many Thanks

bump..see above, posted new questions wrong!!

bump! I am having a bad day lol!

bump again, lol! Hope it works this time

 

[lolly]

Hi,
I am just bumping up this thread, cos somehow i managed to merge my new questions with my previous postings!
Cheers

 

[Billy Bob Bob]

Hi,
I am just bumping up this thread, cos somehow i managed to merge my new questions with my previous postings!
Cheers

age may be against it without looking i cant say,get a gsr engineer to service it and find out the state of play,you will have a better system with a combi but obviously more complex

 

[lolly]

Hi,
Yeah, beginning to think that could be true, gonna now go with the Vaillant ecotec, have read elsewhere that i can get an extra years warranty from the scrappage scheme by sending copies of voucher and invoice. What am i like........arghhhhh
This whole boiler thing has completely done my head in, i think i have done just TOO much research...LOL! But at least i know once installed it will be done properly....hehehee

Thanks again.