New install on an old system.

[Dannypipe]

Hi all.

I've been asked to quote against another installer on a house that has a pretty old system.

The house is very old, and plush internally. Infact it was built in the 1500's.

Guess the heating system is older than me. The client has always been on oil, but has recently taken an opportunity to have mains gas installed.

I've been asked to quote against a couple of others who have quoted to install two cascaded WB 30CDI's, with the Worcester Bosch low loss header.

I take a bit of an issue with this, as the WB LLH isn't designed for a vented system. The way I see it, you could remove the air vent in the top and run it to the open vent but that smacks of a bodge to me (badly).

I'm a bit loathe to seal the system but I've only ever installed LLH's on sealed systems. I don't see why I couldn't have a LLH made up with a proper sized vent on the top for expansion.

Has anyone been in a similar situation? Maybe I should just quote as the others have and seal the system.

I have read on here in the past about people using plate heat exchangers to seperate the boiler from the old pipe work, but have no experience of doing this myself other than repairing a couple of swimming pool boilers in the past!!

It's a nice local job and I want the gig but not if it's going to be agro down the line!

 

[Killy Bing]

Ill ask ali tomorrow danny.

i know we have done atleast one open vented low loss header but that system was huge.
However that was a heat exchanger to the low loss header. Boiler room was 300 yards away.

In my view sealing the system is a bad idea, from the looks of it that place is listed?

give wb a ring and queery them, if that fails look at having one made to your spec.

 

[Dannypipe]

Yeah, it must be listed. It's totally immaculate inside too.

I've called WB and they say their LLH is designed only for a sealed system. I will have to either make one myself which I have no problem doing but will cost me more in pipe and fittings than you can buy one for.

Nice to hear from you BTW mate. How's things?

 

[Killy Bing]

I suppose your other little issue will be how dirty the system is,
I'm betting the oil boiler was a low resistance design so it didn't matter a damn.
a modern boiler hex wont cope?
a spirocross could be an option ?
Give them a look up.
Or you could use a bowmen style heat exchanger between the sealed and open vented systems.

I've seen your quotes and they are ace, i would list why you would not seal the system and the risks.
It might shoot down your rival.

It isn't north pole energy you're quoting against is it?!

Im great, i'm a little faster now too!

i still haven't fixed the leak in the van! I need to asap, every morning its misted up oh so badly 🙂

yourself?

 

[Dannypipe]

Yeah the system will be black as the night.

I've been sent the other two quotes, but just a snip of their wording, no logo's or prices! Their quotes are very thin, with no proper details.

I was thinking about fitting a Spirocross, but then thought it may be simpler and cheaper to stick a couple of ceonventional 28mm TF1's (or similar) on the returns from the headers to the boilers.

I have no idea who it is I'm pricing against. I bumped into the customer and he asked for my number. I had done work for him a few years back but he had lost my number. He's keen for a price asap as he want to award the job to who ever wins and get it booked in. Which is understandable as his existing oil boiler is knackered.

 

[Dannypipe]

Oh and I'm good thanks.

Will it take much to get the leak sorted, did you find out exactly where it's getting in? Sorry about that mate!! Other than that has it been behaving?

 

[SafeGasInstall]

is that house really that big to need 55kw of heating ?

 

[Killy Bing]

The reason i suggested a spirocross was that it has a beefy mesh inside.
maybe put an inline strainer before the tf1?

Oh i haven't pulled it apart yet to see, im sure a bit of mastic will solve it!

behaving? Hmmm
i had fuel trouble like you did 😛

in the end it turned out to be inside the body some of the wiring to the low pressure fuel pump was damaged, every so often to would break and then make after some playing around.

had that replaced and its been fine since then!
Could have been the same story when you had it?

 

[Killy Bing]

is that house really that big to need 55kw of heating ?

That age of building your heat losses are huge, soon as you have a few open fires and a rooms heatloss can easily hit 5kw alone.

 

[Dannypipe]

Jesus, I'm sorry Billy. Why didn't you call me? I never did get round to sending you the receipt for the work I did to the van...but it had a grand's worth of repairs, and a £380 service before I sold it to you, so I genuinely thought it was straight.

Did it set you back much £££.

Oh and I haven't done the heat calc for the property. I've questioned it, but he's had it worked out by a few blokes and it's all coming in at least 55KW. I just have so much on at the moment, that I need to get the quote out and then question boiler size... It's a pretty large property, and as Billy says....the heat loss is a disaster. Getting insulation in a house that age is going not a small undertaking.

Don't know about anyone else on the forum but I've been mental busy. Only had a couple of days off in the past 8 weeks. Worked a 14.5 hour day on Saturday, 8pm yesterday. Just can't catch my breath!

 

[SafeGasInstall]

I am happy for you danny ! keep up the good work .

 

[Killy Bing]

Danny i brought the motor knowing the history!!
do not feel bad!
No it didn't, just an oil boiler service and changing a few taps for the guy 🙂

As far as I'm concerned its a great van and suits me for what i need 🙂

although if you get a chance i wouldn't mind that paperwork at some point? When you have time ofcourse!

If you need a hand at any point just shout Danny, i'll be yours for the fuel money and experience as
i still view myself as an apprentice, i'm nowhere near as fast or experienced as i need to be yet 🙂

 

[Dannypipe]

I will do Billy. I would pay you though mate. You can't pay bills with a pat on the back!

 

[Killy Bing]

I would prefer a pat on the back rather than having a disapointed danny!

 

[Mike Jackson]

I'd be looking at Intergas for an old system. The 22mm waterways are much less likely to give problems with sludge.

 

[Dannypipe]

Probably good advice Mike, but I've been asked to quote 'like for like' so my hands are tied on that front. Apparently I'm the 4th bloke to visit, and the others all suggested a WB. To be fair, I fit a lot of WB and trust the brand.

 

[Killy Bing]

Mike makes an extremely good point tbh.
intergas or separate the two systems?

At the end of the day, would you prefer to price the job to do it right first time and have no issues but risk not getting the job?

or do the job to the other peoples spec, beat them on pricing and have issues down the line?

i have no idea the waterway size on a cdi system boiler but I'm guessing 12mm or smaller?
can someone clarify?

 

[Dannypipe]

Yeah, I don't want the job if it's going to be a ball ache down the line. I know the system is going to be full of crud.

It's worth considering, I'm under pressure to get the quote out. Got a load of bathrooms to quote for too, but I'd much rather win this work and forgo the bathrooms as this will be more interesting for me. So I'm keen to win it.

 

[Killy Bing]

I did the intergas 5 year warranty thingy me bob course. If I'm free tomorrow i will ring up and see if that could be used with you registering the boiler still. Leaving you free with that option.

To separate the systems you need a high water content heat exchanger that can transfer 60kw of heat.
or a pair of 30 kw ones.

then you will need an additional pump. Four in total.

The two boiler pumps to run their own circuit to the low loss head
one from the low loss header to the heat exchanger.
another for the main system.
with that option you could use the WB llh as that would be sealed.



you could bin the low loss header completely.
have each boiler run its own heat exchanger
have both heat exchangers in series for the house side.

 

[Dannypipe]

Like I said, I don't have any real experience of using plate heat ex's to protect the new plant, but surely if the system water is bad, it can damage the new heat ex? How much are they?! 🙂

 

[Killy Bing]

I have no idea!
ive only just started do the spec for jobs :/

People care to add ideas? Please!

 

[Dannypipe]

No worries, I'm going to give the customer a call tomorrow and have a chat with Intergas.

Pretty sure I'm going to quote to fit the two 30cdi's and make my own LLH. Keep the system open vented, and fit a pair of 28mm filters on both the returns. That keeps it fairly simple.

If anyone else cares to comment, I'm always open to other opinions.

 

[Kev the gas]

Hi Danny hope you and the family are keeping well, nice to see you back on the forum.

I cant offer advice on the specification for the boiler but one piece of advice:-

When a customer has already had 3/4 quotes already and need a price asap I normally find they have already made up their mind of an installer, they are still trying to convince themselves they have made the right choice. Or the job will never happen !!

Try not to waste too much time on the estimate unless you think it will help your knowledge in the future.


Kev.

 

[Ermintrude]

Two ideal logic plus 30kw on a cascade with LLH open vent is simple and works a treat. Only problem u got is the listed status. Do they have consent for flues and plant!!? Magnanaclean 28mm on return from LLH. Boilers need to be co current connections when in cascade. Boiler 1 gets flow first and ret seconds and boiler two gets flow second and return first.

 

[Dannypipe]

Hi Kev, good to be back on here.

Family are all well thanks, adding one more to the clan as of February.

I hope you and your family are well too mate. I still haven't got round to fitting that panel I had off you!! Ha. It's in the mother in the mother in laws garage waiting until I have a quiet week. Oh and can find a cheap pump station!

I'm not going to waste too much time with the quote, but I do want the job over some of the bathrooms I'm quoting for. I'd rather earn a little less and not have the head ache of organising all the other trades if I'm totally honest!