Nobody wants my friend's 4K+ Combi Boiler upgrade job!

cormie

My friend is looking to upgrade their heating system and has opted to go for a combi boiler & pump using Google Nest to zone up and down stairs, remove the existing cylinder and turn the hot press into a wardrobe, blank a few pipes, chase a few others etc.

It's a straight forward enough upgrade from what I can tell, but they've had trouble getting quotes for the job even though they are telling everyone it'll be about 2 months before they have the funds to proceed, so it's not like they are looking to get it done immediately.

I mentioned the upgrade before and one quote, it seemed like the plumber was charging €500 extra for a boiler feature that didn't exist, then 3 guys who I was recommending to my friend, one based on info they provided over boards, and then two guys they subsequently recommended as they were too busy themselves, were all too busy to quote and I never heard anything back from the last 3 messages I sent to one asking could they come and take a look to quote, then the other came to price the job but before they sent on the quote, they got two big jobs and won't be available now.

Another guy who's van I passed in the city came and it all looked like no problem to him and he seemed up for the job and he came across very well has had a sickness in the family so hasn't been able to send on a quote.

So if anyone can recommend anyone for a job in Dublin 5, please let me know. I've attached a pretty detailed plan and description of the job (NOTE: Diagram pipe layout was drawn by me and is just reflective of position of piping I know about but does not reflect different pipes for hot/cold/heating etc, only where the actual pipes are)

Looking for SEAI and HRI registered if possible.


Also, just on the Google nest thing, I believe to qualify for the HRI/SEAI money, the job needs to be at least €4,500. So I'm thinking would it be best to get the Google Nest direct from Amazon for about €220 delivered (it tends to drop to about £188 delivered), or should the plumber get it and then the VAT can be reclaimed through the HRI refund maybe? But of course if the plumber puts a mark up on it, it would make more sense to go through Amazon, but then again, if getting the nest from the plumber means the difference of getting the grant/refund or not, it would be best to get it through them?

AndyBoBandy

You would need 2 Nest's for dual zone though as a single Nest only does heating & water, and can't do upstairs/downstairs zones

cormie

Thanks for the input, yup, I should have mentioned I needed two in the OP, I mention it (although not very clearly) in 4 & 5 in the plan, but yeah, so it will cost about €440 including VAT for two through Amazon, which could make up the difference between qualifying for the HRI/SEAI or not.

I'm not sure where the plumbers may get them, but if they work out at less than €220 each EX VAT, then it's all the same if the VAT can then be reclaimed through the HRI maybe?

cormie

Hey folks, my friend had another plumber in to quote who suggested EPH Ember: http://emberapp.ephcontrols.com/

they said it's about €300 less for the same thing.

2 Nests will cost about €450.

Has anyone any thoughts on this? My friend has the Nest carbon monoxide alarm and smoke detector and I believe they can all communicate with eachother so for example if the alarm detects carbon monoxide, it can make the thermostat switch the heating off, this alone could be worth the extra money perhaps, or maybe not?

Any other input would be great

.243

cormie wrote: »

Hey folks, my friend had another plumber in to quote who suggested EPH Ember: http://emberapp.ephcontrols.com/

they said it's about €300 less for the same thing.

2 Nests will cost about €450.

Has anyone any thoughts on this?

im about to install one in my own home,had a quick look at the installation instructions, seems straight forward

cormie

Did you consider the nest instead and if so, what made you go for Ember? Just the price?

cormie

Hey again folks, my friend got somebody for this in the end and they are starting today. They were mainly communicating over email and he said he'd be getting a Viessmann 30kw boiler initially. They spoke today and he said he had a 26kw and my friend was worried this wasn't enough 2 have 2 showers running consecutively and that other plumbers were suggesting at least 30kw?

The plumber said they could change it for a 35kw if my friend wanted, that it would only be an extra €80/100 or so, but that no combi boiler will manage 2 showers at once?

Is there anything to be wary of here at all?

Of course, I know the pressure would drop if a second shower was turned on, but as long as there's hot water, so just use less cold, then it would be ok for 2 showers at once?

antoinolachtnai

You mean two showers at the same time (concurrently)? I think your friend should listen carefully to the plumber's advice. If he wants two showers at once a combi is probably not for him.

cormie

Sorry, yes, two showers running concurrently, not consecutively

I rang Veissmann after posting here anyway and spoke to their technical department, the guy there also said there's no combi boiler out there that will run two showers at once, but then after digging a bit more, it's certainly possible, but just not at such a high pressure per shower, which is fine really as two showers going concurrently will be rare anyway, but at least that when it does happen, it's just going to be a case of the pressure dropping and both people will still be able to have a wash in warmth

Have discussed it with the plumber too and all is good

cormie

cormie wrote: »

Sorry, yes, two showers running concurrently, not consecutively

I rang Veissmann after posting here anyway and spoke to their technical department, the guy there also said there's no combi boiler out there that will run two showers at once, but then after digging a bit more, it's certainly possible, but just not at such a high pressure per shower, which is fine really as two showers going concurrently will be rare anyway, but at least that when it does happen, it's just going to be a case of the pressure dropping and both people will still be able to have a wash in warmth

Have discussed it with the plumber too and all is good

You asked Viessmann the wrong question you should of asked them is it possible to run two showers at the same time if I know there not going to work right together, their answer would be "yes that is possible"

It's not Viessmann first rodeo so they are fully aware of what works well and what can end in cold/hot/cold/hot tears.

antoinolachtnai

Installing heating in a home is such an expensive project to do, especially when you are using the good gear like Viessmann, and I think it is important to get a result that you are going to be really happy with.

cormie

Yeah, I think they'll be really happy with this. And the long term plan is to eventually not need the tenants there so there'd be less demand for showers etc then too

antoinolachtnai

The issue isn't just of splitting the pressure evenly between the two showers. The pressure or water flow might split in an unpredictable way, i.e., one shower might get three quarters of the pressure and the other shower might have to make do with what's left.

I agree with the other poster that you are not using expert advice as it is best used. I would not install anything unless it is in accordance with the manufacturers recommendations, certainly not top-class gear. The manufacturer is not recommending what is proposed. The manufacturer is just saying that it might be ok. That is not a recommendation. (And no manufacturer will recommend installing a combi where it is prohibited by local regulations, as it is in Dublin.)

If they really need showers at peak time ( it's not unusual, you need that for people going out to work or school early in the morning) and they definitely need it in the short term, I would get a solution that meets that need (a fast recovery cylinder and a pump basically). But it is really up to them.

cormie

Thanks again for the feedback.

Yup, it's not that they are recommending it alright, just not saying it won't work. The plumber has said that it should work fine and it's definitely going to be possible for two people to have showers concurrently, just with a dip in pressure. There's only one shower in the house at the moment by the way and it may be a year or so before another goes in, so if it happens to be a case that when the second is installed, that one shower has a trickle when the other has almost full pressure, hopefully it will be easy enough to adjust then.

They decided to ditch the cylinder for the extra space in what will no longer be the hot press.

cormie

cormie wrote: »

Thanks again for the feedback.

Yup, it's not that they are recommending it alright, just not saying it won't work. The plumber has said that it should work fine and it's definitely going to be possible for two people to have showers concurrently, just with a dip in pressure. There's only one shower in the house at the moment by the way and it may be a year or so before another goes in, so if it happens to be a case that when the second is installed, that one shower has a trickle when the other has almost full pressure, hopefully it will be easy enough to adjust then.

They decided to ditch the cylinder for the extra space in what will no longer be the hot press.

My advice to you as a senior technical engineer for another boiler manufacturer is two showers don't work very well for numerous reasons.

You'd be better fitting a electric shower so you have a second source of hot water in the event of the boiler breaking.

Jack the Stripper

What qualifies one as a senior technical engineer?

Jack the Stripper

Jack the Stripper wrote: »

What qualifies one as a senior technical engineer?

Pain and hardship.



(Less contrary answer, 30 years qualified City and Guilds gas service engineer, 15 years being sent to represent boiler manufacturers determine product failure or installation error for any warranty boiler issues then documenting findings )

cormie

The guy from the technical department at Viessmann said it would have no affect on the boiler at all, that the boiler will just output what it outputs and if this is split along the way it won't have any affect so shouldn't risk the boiler breaking whatsoever?

Also it was advised that two electric showers are not possible to due to some restriction with ESB not providing enough something or other to each house?

antoinolachtnai

It won't damage the boiler. It just might not work very well as a shower.

You could have one electric shower and one shower off the combi.

ted1

cormie wrote: »

The guy from the technical department at Viessmann said it would have no affect on the boiler at all, that the boiler will just output what it outputs and if this is split along the way it won't have any affect so shouldn't risk the boiler breaking whatsoever?

Also it was advised that two electric showers are not possible to due to some restriction with ESB not providing enough something or other to each house?

Just use one electric and one off the Combi. Two electric showers are possible using a priority switch, this will allow only one at a time to work.

All recommendations is to not use two showers of the combi,yet you are adamant to pursue it. Stop and think.

cormie

cormie wrote: »

The guy from the technical department at Viessmann said it would have no affect on the boiler at all, that the boiler will just output what it outputs and if this is split along the way it won't have any affect so shouldn't risk the boiler breaking whatsoever?

Also it was advised that two electric showers are not possible to due to some restriction with ESB not providing enough something or other to each house?

When you open a tap on a combi the tap itself works as throttle impacting on the temperature,you will also have to take in to account the distance between the boiler and the tap as it can take quite awhile to feel the change in temperature unlike stored water where the temperature is a constant irrespective of tap position.

When you open a second tap you can impact on the temperature at the first which is then made worse if both taps have people at them opening and closing the taps to get the desired temperature this is made worse again if your using thermostatic showers, add to this seasonal temperature variations and water pressure issues running two showers off a combi becomes a pain and the house holders have to adapt to a hot water system that can easily vary in temperature.

When looking at hot water needs it preferably to design a system that works, in your case I'd advise (as mentioned above) one shower off your combi(the larger the kw output the nicer the shower will be) and one electric shower so you always have a secondary source of hot water which you lose when you remove your stored hot water with its electric immersions.

cormie

Thanks again for the input everyone. I just had a call off another boards plumber after seeing the thread and explaining a few things.

I understand the uncertainty of using the combi for two concurrent showers, my friend is ok with that and every plumber who came to assess the job said it should be fine, but just to expect the dip in pressure and variance in temp, which they are ok with too.

It's going to be really rare that two showers will be used at the same time anyway, and it's going to be at least a year until the new shower is installed too I'd say.

The plumber who phoned said the only thing of concern is that maybe the pump (it's TQ200 2bar) won't be enough for 2 showers, but it could be fine and you won't know until you install the new bathroom really, but that it's easy to change/upgrade if necessary, but probably won't be an issue.

He also said just to maybe check the level in the tank in the attic that if all the water in the tank is used, if the pressure from the mains isn't great, that you could use all the water in the tank and cause an air lock, he said only likely to happen if two showers going for a long time each, so would be very unlikely to happen.

The suggestion of an electric shower is definitely a great backup option if it doesn't end up working well, but I guess it won't be clear for another year or so