New Install & Boiler Advice.......

[Terry lambert]

I havnt fitted them but have also heard some good things from installers on here.

You will lose some flow through your boiler and internal pipework.

The flow at a kitchen tap is often restricted and so this may not give you an accurate reading

Ideally you would want more than the boiler can supply

As per micks post who really knows his stuff, by the time you have a frictional loss through pipe work, boiler ect you may get 8 ltrs min which would be disappointing.

In that case you may want to reconsider.

Based on your flow rate and if you have 2 plus bar pressure and you were determined to have a combi, I would fit a 30 kw. You may not get the best out of the boiler but you would get the best out of your existing main.

You could upgrade your incoming main? Check to make sure all stop cocks etc are fully open and their are not a lot of bends and restrictions.

You could leave the cold tank in the loft and pump the cold down to the cold feed on the boiler in the airing cupboard although there would be the noise
of the pump and you would not have gained anything space wise.

 

[Humour]

Ideally you would want more than the boiler can supply

As per micks post who really knows his stuff, by the time you have a frictional loss through pipe work, boiler ect you may get 8 ltrs min which would be disappointing.

In that case you may want to reconsider.

Based on your flow rate and if you have 2 plus bar pressure and you were determined to have a combi, I would fit a 30 kw. You may not get the best out of the boiler but you would get the best out of your existing main.

You could upgrade your incoming main? Check to make sure all stop cocks etc are fully open and their are not a lot of bends and restrictions.

You could leave the cold tank in the loft and pump the cold down to the cold feed on the boiler in the airing cupboard although there would be the noise
of the pump and you would not have gained anything space wise.

Ok, all loud and clear. Thanks for excellent advice and tips. Will check on the only stop kock I know of in the house and will speak with the water company. What is an average flow rate I should be aiming for?

Im not determined to have a combi specifically, but would prefer to have a simpler system with no water above my head, and no vent hole in my living room a small child can fit through......ideally. I am however determined to reduce my ridiculous gas bills, uneven temperature around the house and have a working stat in every room with an overall system controller belonging in the 21st century, not the 18th. lol.

Regards

Hum

 

[Terry lambert]

2 bar pressure with 14 ltrs min is quite common in some parts of London
With a combi I would ideally like 18 ltrs a min with more than two bar pressure.

It's a matter of being aware of the downsides to fitting a combi with an average to poor main and then either accepting it or looking at other options.

As previously said though I would not trust the flow rate reading from your kitchen sink ad gospel.

I would also make sure the stop cock in the pavement is fully open

You could look at your neighbours water flow rates either side of you because yours should be the same other than internal pipe work restrictions

 

[mickyg]

where abouts are you exactly ?

 

[ServiceNumpty]

I have fitted lots of the older remehas and there have been issues with them particularly at the 2 to 3 year old mark. They are a nice looking light boiler that use the standard giannoni stainless steel heat exchanger, parts replacement are fairly straightforward and you should get 5 years parts and labour warranties on the new range, they are also supported warranty wise by heat team. They are now not my first choice but still not much different from most of the mid range boilers out there, so if a customer wanted one fitting I would fit them as I know they,re little foibles. The remehas came in 28, 35 & 39kw versions so the 28kw would suit.

 

[Humour]

@terrydoh - Thanks for the guideline. I'm still not 100% clear if the reason for the higher water pressure is so for the purposes of the shower only?

I personally think that the taps pressure is more than adequate. The leccy shower is a bit on the low side but now that I have been using it for a few months I have got used to it, provided I can get the same result with a condensing combi and most importantly get consistent water temperature output, I think it will be acceptable. The shower I inherited is only a 7kW unit with a 15mm pipe coming down from the loft and that wont blow your head off but does the job.

I've read enough about the pro's and con's for the combi system an Im happy to live with the cons, but of course being able to minimize them if possible is always a plus

In terms of increasing pressure from the mains, what do you think of THIS solution?

Loud and clear on the mains. I will check the stopcock in the kitchen tonight and will try and find out where my mains stockcock is located and have a looksee.

@ michele - thanks for the feedback. I also read that some boilers had troubles, but these posts were between 2005 and 2008. The more recent discussions from 2010 onwards only had good things to say, especially from installers. Dont get me wrong, my first choice was Wocester until I got to read end user opinions and circumstances regarding breaking of boilers etc. then I moved to research Vaillant and saw more of the same so in terms of a condensing combi now Im just trying to find something that is percieved to be reliable over a medium long term, doesnt have attrocious technical support for when my repairer needs to get to talk with manufacturer, and comes with a reasonable performance and efficiency rating.

@ mickyg - Im in Houghton Regis/Dunstable in Bedfordshire.

Regards

Hum

 

[Terry lambert]

You need a minimum pressure for the boiler to operate, and if the pressure is low, by the time it gets up to loft and through all the frictional loss of fittings etc then it could be pants.

On the upside you may have 2-3 bar pressure and all is good.

Accumalators are great, fantastic and lots of other superlatives for systems with low pressure and flow but they can becas big as a cylinder to make them worth while.

If your lucky enough to get Micks interest in the job, most of your troubles should be at an end and solutions or best options found.

 

[Humour]

I've been looking into water pressure and flow and its being claimed that water companies have to guarantee 1bar and 9Ltrs/pm.

If law only requires them to guarantee those numbers, then its difficult to imagine how one can ask for more than what they are getting if its not below the values required by law in which case I dont understand where the ideal number of double those values are coming from. I mean how many out there are at 3bar and 18Ltrs+??

Tbh Im not too worried about space, the current cylinder cupboard can accomodate both a combi and one of those pressure/flow cylinders.

First things first though, check stop cocks and get water pressure and flow measured by someone.

Regards

Hum

 

[mickyg]

sorry bit far for me

regards remeha, they have bought out a new range, Im hoping its the same but with all the faults sorted. I like the design.
For now I'd recommend atag or glowworm.
I wouldnt worry about improving your main until you know for sure you need to.

 

[vulcancontinental]

Is it ex-council? What street?

A lot of that area is still on iron pipework in the house for the domestic hot and cold and I saw many last year still using the glavenized cylinders that were installed when Houghton Regis was developed.

I imagine the pressure would be OK and flow rate also in the area but don't believe the 1 bar story; it's true but there's small print in the relevant act that allows a water company to go lower than they in certain circumstances. I don't think for a moment that will be the case where you are.

I work for a boiler manufacturer so can't give you advice but don't pay cheap for the boiler or the installer. Get recommendations for the installer, not just the boiler.

Keep a combi near the tap you use most or between the appliances (it's a pet hate of mine). Turn the hot tap off in the kitchen when a combi is 35' away in the loft and all that lovely hot water in the pipe you've just paid to heat becomes stationary and grows cold. Every time.

I've done it, it's no big issue and there's no real problem but it just annoys me personally to see waste. If you're on a meter you're running cold away till the hot becomes usable at the tap also.

 

[Humour]

Thanks for the useful feedback.

Yes I believe the house is an ex. council. The street is Tithe Farm road

The water piping coming into the kitchen from the ground is plastic with a plastic stopcock. I checked that yesterday and its fully open. Following that the piping continues in plastic until it dissapears into the cavity where the toilet/bath waste pipe (iron) sits. Everything else I have seen re; the boiler is copper, but not sure what kind of piping is used in the waste cavity.

Tried to call Veoila water cust. service yesterday but their service is currently unavailable Walked along the street but all I saw was CATV holes and covers. On the opposite side of the street on the pavement there was a manhole, well quarter size of a man hole with no markings on the cover, need to figure out how to lift it to see whats underneath, but so far cant locate the water supply from the street.

I know what you mean about the piping. The kitchen has been extended into the garden and so the hot water takes about 40 seconds to reach the tap, but it will be a right PITA to put the boiler in the kitchen as the pipe work will be hard work with a concrete base floor. I think the landing cupboard location will be the most suitable as its 3M away from the gas metre, 2 metres away from the bath/shower and in terms of volume of water consumed I think the shower will be taking that crown so I rather get that right than the kitchen tap. I know its wasteful and I hate waste too, but I can always put in a dish washer and I dont do gardening (apart from kill it ) so it balances itself out in terms of waste

Who can do the flow rates and the pressure tests for me, heating engineer or plumber? Or is it reasonable to press the water company to come and do it and give me the location of the street stopcock?

The boiler choice is still the biggest gamble I have to make and its less than clear what to go for. Allot of reccomendations out there and allot of counter arguments being voiced. Researched WB,Vaillant, Remeha, Potterton, Gloworm, and none are decisive.

Which Gloworm model is the best in your opinion Micky? I do like the look of the Glo's and my current backboiler is Glo and has been in for 20 odd years.

Regards

Hum

 

[Terry lambert]

The heating engineer that is quoting for your install should do the flow and pressure tests.

The problem with research can be.

Earlier models of the same Glow worms that are around now had some problems, but they have been sorted. ( they are also owned by Vaillant )
And again a lot to do with bad installs, people pay a pittance for an install or are unlucky and get a cowboy and then want to blame the boiler!

So you may read a bad review about a boiler but it could be an earlier version or due to a bad install

 

[Humour]

Fair comments and I can appreciate your point of view Terry.

From my point of view, Im budgeting to invest 4-5K of my hard earned cash into a system which regardless of the number of variables involved, boiler/installer, etc. equate into an end result that I'm going to have to live with.

Doing my best to research good and bad calls based on experience, can only be viewed as a positive even if it muddles the water sometimes. At least with a product its a relatively straight forward gamble, you get to find out who has design issues and who provides bad support and remove them from the consideration pot.

Making a judgement call on a quality installer on the other hand is a much more difficult judgement call, especially one's who want to ensure customer satisfaction as well as being trained to install the boiler of choice and provide a decent warranty/suport term. There are no guarantees I wont end up with a cowboy whether I pay little or allot. and I certainly can't get an average opinion on their work quality and customer focus. I could ask for references, but I doubt they will let me speak with anyone who is in any way unsatisfied

From the point of view of the boiler size, I'm happy to go with a combi subject to a few details being firmed up re; mains. Something that has confused me however is that I followed the DYInot's B&C Heating FAQ and used the linked boiler size calculator, which based on my property circumstances equates to a 9.92kW output

.
Where it does get confusing is that the guide says if the boiler is over powered, the eficiency and wasteage goes up, yet all reccomendations from installers have been to fit a 28kW boiler as a minimum. So what am I missing here as there is a clear contradiction between the two?

From the point of view of the boiler, also based on the DYInot B&C FAQ reccomendations and opinions, I have made a short list based on my preference of boiler appearance and capability, but not necesserily correct boiler output for the property. From those listed below, an opinion on which one's are a potentionally a bad call would be appreciated.

1. Veismann Vitodens 200-W
2. Gloworm Ultracom 35
3. Vokera Linea One
4. Broag Remeha Avanta Plus 35C
5. Vokera Unica HE 32
6. Gloworm Betacom2 28
7. Vaillant ecoTEC 630

Muchos gracias for the feedback thus far. I am learning alot during this process

Regards

Hum

 

[Terry lambert]

The 28 kw on the boiler epwill be for the hot water side, the heating side would be rated at 24 kw

Combis are often oversized for hot water purposes a heat only would be different.

And so

Modern boilers will modulate to suit the heat load, but this isnt nessacarily a good or efficient way to do it. With some of the combis you can range rate or lower the heating power so that they condense for longer periods, are more efficient and correctly sized for your system, but you can still have more power for hot water ( more hot water, if you have the incoming main)

The new Vaillant will do this automatically with an intelligent gas valve etc

The research side on a product as I said can also be problematic( reasons in earlier post)

A couple of the makes you list, I don't install and so can't comment, I still go with Vaillant or glow worm

 

[Humour]

Im really not keen on the Vaillant based on what I have read overall.

I think I have finally narrowed it down to two choices, subject of course being able to find someone accredited to install and maintain who isn't too far from me.

My final choices are:

1. ATAG A325EC
2. Veissmann 200W

Despitebeing a big learning curve I have learnt allot and now understand why certain additions make sense, such as weather compensation, etc.

Regards

Hum