New install on an old system.

[Dannypipe]

Now can someone comment on the pumps?! LOL

I'm having a bit of a crisis of confidence as I've worked along side my dad my whole working life, but I'm doing this one off my own back. Dad can come and help me if I want it, but I want to leave the old boy in peace! I'm sure I'll be fine, but I don't want any slip ups. I sound like I'm 20 not 35!!

 

[SafeGasInstall]

Thanks for that.

Can you explain why you have to configure the f&r's like that? To maintain an equal flow rate I'm expecting.

I'm also going to quote to fit a sequencer though looking at the other quotes, they haven't. I've installed one before and it's worked well. I used the Warm World model. In fairness it broke after two years (a relay went) but the new one has been in a couple of years now and is all good.

Sequencer ???

 

[Dannypipe]

Not fitting the sequencer, he didn't want to pay the money. I think they're great. Basically it fires one boiler if demand is low (say it's doing one zone only or the ho****er coil). Then it automatically switches with a timer which boiler is firing (so they wear evenly).

Then if the pipe stat picks up too much of a temp drop, it brings both boilers in. Saves gas, and less wear on the boilers. I've photographed the last one I fitted and put it up on here. A relay went buzzzzzzzz in it though. So had to change it last winter.

 

[SafeGasInstall]

Danny do you have a link pls 🙂
is sequenser used instead header ?

 

[Dannypipe]

Intelligent heating - Save money on your heating bills

No mate, you still need the header (depending on the system of course) other cascades don't need headers as we know.

 

[julesverne]

knew it was in the 70's not ever likely to get close to that in the area i work biggest install i've done is 35kw but it would be nice to read up on it out of interest.

Hi Jules. It's fine to cascade boilers up to your limit. I've cascaded oil boilers to over 80KW in the past, but that was working alongside my dad who was a commercial fitter for years. Oil didn't even have a commercial qualification until about a year or so ago. Croppie was one of if not the first one in the country to qualify for it.

By the way the limit with gas is 70KW not 75. Here's a snip lifted from Kirk a couple of years back.

~ domestic is up to 70kw appliance, or pipework up to 35mm as long as it contains a total installation volume of less than 0.035m3, a U16 meter can be used depending on overall volume not exceeding 0.035m3

 

[stevetheplumber]

in the days before the distinction on comercial we fitted 4 vaillants onto some 4 inch pipework via a low loss header worked fine but this was before condensing we had the header made up in welded steel

 

[Dannypipe]

I don't tend to fit many small boilers, but I don't regularly fit 60KW. Most of my stuff is between 30 and 40KW. I probably only do something like this every couple of years. I will photograph the work as it progresses and put it up on here. I'm starting on one of the out buildings first though, and changing the oil fired boiler for an 18ri.

 

[Ch4 plumbing]

I know it's a bit late to reply about the F/R pipe configuration but I've always known it as reverse return, and the reason to do it is so both boilers workload is equal, if you pipe them any old way one of the boilers will work it's self to destruction while the other idles. Hope that helps mate.

 

[Dannypipe]

I am aware of that thanks ch4 but any advise is always welcome.

 

[Killy Bing]

Why don't you wire a pipestat as a room stat to the low loss header and set it to 60?

 

[Dannypipe]

For Billy.

 

[Dannypipe]

This is the LLH I'm proposing for the install. I know the 54mm is over kill but I don't want to restrict the existing flow header on the system. Infact I don't want to alter that at all, as I know it works. I got the old boiler running. Sounds like a bag of nails, but helped with cleaning the system.

 

[Killy Bing]

Over engineer and earn a few quid less.

save a few quid and cost yourself in the long run.

no brainer on this type of install

 

[Ermintrude]

If you had coupled two logic heat only 30kw in parallel with reverse returns you could avoid LLH and only need one pump and two Aav. But it's horses for courses! For the cost of the LLH you could have a half day?

 

[Dannypipe]

I couldn't use logic's as I was quoting against other engineers who specified WB's and LLH. The bloke got 4 quotes. One company (the most successful small heating firm in my area funnilly enough) didn't reccomend a LLH and suggest one boiler not two. He told me about this, and how he immediately discounted their quote. I was pushed for time so I matched the others quotes, but with a couple of caveats. Caveats that will make me less money than the competitors quotes, but do mean the system will work better.

They all wanted to use the WB LLH which for me was a bad move. Be interesting to see how much this costs me. I'm not fussed about using two pumps. It's another £80. Won't break the bank.

 

[vern]

Jeez I am here pal, piece of pi55 have you won it? If so I have a design although I would have fitted an FS 42 CDi as they have 28 mm connections, and a plate heat ex, but I understand client wants 2 x WB's so no prob

 

[vern]

Also Danny wants the max head height from tank to top of WHERE LLH will be mounted in meters?

 

[Dannypipe]

The heat loss calc was over 40KW Vern so I couldn't have gone down that route. I don't think it's a problem stepping straight up to 28 from the boiler connections. Do it quite regularly of other installs.

Anyway, I'm always open to learning something, so please let me know your thoughts. The height from the tank to the top of the LLH is about 4.5M mate.

 

[vern]

The heat loss calc was over 40KW Vern so I couldn't have gone down that route. I don't think it's a problem stepping straight up to 28 from the boiler connections. Do it quite regularly of other installs.

Anyway, I'm always open to learning something, so please let me know your thoughts. The height from the tank to the top of the LLH is about 4.5M mate.

Right pal, 2 x 30 cdi conventional boilers, into a Broag 80 kw LLH, VERY COMPACT, 4 x 1"" female trappings for both boilers F&R'S, pipe up from LLH TO BOILER IN 28 mm, mount a Grunfos 15/60 on 28 mm pump valves, on speed 3 on the return, with a magnaclean etc before pump on return to each boiler, wire these from boiler PCB for overrun. DO NOT MOUNT ANY VALVES ON FLOW

From system side of LLH which has 2" male connections, so use 2 x 2" MI X 54 mm copper, from flow out of LLH expansion, then cold feed, then system pump with zone valves as required and ABV ETC, system pump to fire off zone valve microswitches, LLH has 2x 1/2" trappings one at bottom for DOC, one at top also, place in there a tee containing a Nabic PRV RATED at 1.5 bar assuming Round 5 m head, then above PRV an AAV, THIS WILL PROTECT THE SYSTEM SHOULD THE EXPANSION EVERY BLOCK UP belt and braces.

The boiler pumps won't pump over as they are against a good resistance of the hex they will also run cooler and last longer, the LLH ALSO BECOMES THE NEUTRAL POINT TOO!

Dont worry about WB's ON THIS LLH their pipes can go down first even on open vent, hence the built in AAV on their hex.

This will work a treat no problem done a few like this

 

[zeebeedee]

If you fit an ideal logic fit a magnetic filter, the pumps/diverters on these cant handle even a tiny bit of dirt!

 

[Dannypipe]

I'll compare the cost of the broag LLH Vern. I like the idea of the PRV. It is belt and braces though!

I won't be messing with the existing header, apart from to remove the old zone valves and fit new ones. One of the zones is run off 42mm tube the other 54, but that's only because its been an old gravity system. In my opinion the pipe sizes are totally over the top, but as I said, I won't restrict it from my header as don't want to save a few quid, and regret it.

The trouble is, the money isn't in there to do everything I want to do to the system. (Is there ever?) I'm going to have to make some compromises that I don't want to as is.

 

[vern]

I hate jobs where you have to compromise, especially for a few more quid, you can make the system sing! But that's what happens when they get too many quotes!

won and installed one recently where she had 7 quotes, simple job, no one listened to her, she had a fully pumped ideal classic, it was too small and the pump noise in her daughters bedroom was loud, 4 gave her a combi quote, the other 3 heat only with new pump.

shame she had gravity showers that a combi would have blown to bits not one of them mentioned this lol 4 out

i installed a WB system boiler job done ( other 3 out)

 

[Dannypipe]

Yeah, I would have liked my original quote accepted and could have got the system as I wanted. As it is, I've price matched another quote, and am giving more than he would for the same money, so I really can't gild the job at all.

How people find the time to get 7 quotes is beyond me. The combined wasted time for all involved would run into days!

 

[vern]

Yeah I know pal, if I had known though I may have not bothered lol, school teachers lol

Donthe job to a good standard pal and you will get more work and respect

 

[Dannypipe]

I'll keep you posted mate.

 

[Dannypipe]

and thanks by the way.

 

[Dannypipe]

 

[Dannypipe]

Did finish this a few weeks back. Just got photos off my phone. Wiring isn't the as tidy as I would like but it's only temporary as I'm going back to wire the new Honeywell intelligent TRV system in the New Year. Couldn't leave as was as I found loads and loads of live earths in the wiring centre and I had to alter it to fit my new zone valves. (Here's two of many!!)

Anyway, Customer very happy with it.

 

[Nostrum]

Nice install Dannypipe, what's in the control box then? A 10 way choccy block? 🙂

 

[IDCHAPPY]

Now can someone comment on the pumps?! LOL

I'm having a bit of a crisis of confidence as I've worked along side my dad my whole working life, but I'm doing this one off my own back. Dad can come and help me if I want it, but I want to leave the old boy in peace! I'm sure I'll be fine, but I don't want any slip ups. I sound like I'm 20 not 35!!

This will be my situation in a few years :lol:

 

[IDCHAPPY]

Nice Install Danny, I'm sure your old boy will be proud 😀

 

[Dannypipe]

Cheers lads. Yeah there are a couple of strips of choco block in the adaptable box and a load of relays. Hence the size of it. It's got a high limit stat on the header and low limit stat with the frost stat and then relays to split the switch live. As said the electrics were a bit of a nightmare. Probably took me two or three full days. I added a temporary stat to the first floor which is the Salus box above the main box. Got to be honest, I really enjoy wiring controls even if they sometimes leave your head like mash potato.

 

[SafeGasInstall]

Welldone Danny , you got a link for that control box ?

 

[Dannypipe]

Don't know if this will work Stan. Page 398 of the toolstation catalogue. Adaptable boxes.

The neons I bought from an electrical wholesalers.