Condensing Boiler replacement for my conventional boiler

I need to change my boiler as it is now very old. I see that from April 2005 it will be necessary to fit a condensing boiler.

I want to get away with as little change to the pumped CH and geavity HW system that is currently in the house.

I will need a standard flue kit. My existing flue is balanced so must I put in a flue stack up to roof level and does it have to be insulated etc.?

Can I have an open vented pumped CH system and gravity HW with a condensing boiler?

What other changes might I have to make?

Thanks for you time. I have looked through loads of posts but see conflicting comments.

Andy Kaye

Reply to
Andy Kaye
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Sounds like you're in an identical situation to me. I'm having a new condensing boiler fiitted in April. My existing boiler is 28 years old.

Every plumber that has been round to quote has said that the system needs modifying, ie, changing from gravity semi fully pumped to a fully pumped system with a system boiler.

IMHO, if i'm spending all the money on a nice new highly efficient boiler...we may as well go the extra distance and spend a bit more to get it running optimally. It's really not that much extra.

Reply to
RedOnRed

I don't disagree. But I want to know that my money is being spent properly. If i know what is required I can sort of guess how much it might cost.

If a bolier costs =A3800.00 and valve etc cost another =A3100 an it take a day to install then =A31200 is a resonable price. But llokig at posts here,it could be =A32000.

Reply to
squidk

You will need to get away from the gravity HW and go fully pumped...

There is no reason it has to go up to the roof. Where (and at what height) does it currently exit?

Why would you want to? conversion to a fully pumped sealed system is pretty straight forward.

You ought to bring the controls up to standard, so a stat on the HW cylinder, and room stat plus thermostatic rad valves elsewhere if not already fitted.

Depending on the state of the rads and pipework, it may or may not take well to being pressurised.

Reply to
John Rumm

Thanks for the info John.

I will have to look up what is necessary to change the HW from gravity to fully pumped.

I read that it is not a good idea to have too many thermostatically controlled radiator valve as it cuts down the efficiency but we only have them in bedrooms.

As for the original balanced flue it exits the house at chest level. With a wall hung condensing boiler the exit for the flue will be at about 7 ft. I didn't know if there were any building regs for the condensing boiler flue like with conventional flues. I seem to remember my father having to build an insulated stack up to the roof in the past.

I expected to add a cylinder stat. and upgrade my room stat. and chnage the programmer so I guess I am a little better prepared now.

Now to find a corgi fitter who doesn't charge the earth.

Reply to
Andy Kaye

But you don't have to have a pressurised system, you can buy condensin regular boilers. I'll be fitting a regular condensing boiler open ven with open vent dhwc this week as a new installation, because it is holliday flat so the frequent changes of user don't have to be educate about filling loops. Open vent systems though hasstle for the installe (particulalry if he designs his pipe runs badly) are more use friendly.

On this post don't forget all the above plus with a major change lik upgrading the boiler the cylinder has to conform to part L 2002 also so that undoubtedly needs changing.

Of course you can apply for exemption from Part L, say for instance yo are 95 years of age and don't expect to live long enough to benefit fro the extra capital cost.

Costs?

Very high quality condensing regular boiler (and horizontal flue) wit

5 year manufacturer's parts and labour guarantee 800 gbp.

DHW Cylinder

141 gbp

S Plan (because it's the best) CH control system (includes everythin you need) 76 gbp and a new pump 65 gbp.

TRV's from BBQ 5 gbp each

Pipework and fittings 200 gbp

cleanser and inhibitor 28 gbp

REmoval disposal of old boiler and cylinder? 200 gbp.

Labour two days for a quality heating engineer and his side kick; 80 gbp.

Extras? You may need new header tanks

-- Paul Barker

Reply to
Paul Barker

If a bolier costs £800.00 and valve etc cost another £100 an it take a day to install then £1200 is a resonable price. But llokig at posts here,it could be £2000.

----------------------------------------------------------

I'm being quoted around £2100 inc VAT to do all the work required for me and for one man it's a good two days work.

The work includes...

powerflush, boiler replacement to a Worcester Bosch 28 HE condensing system boiler, remove and brick up old flue, replacing programmer with a 7 day one,

4 TRV's to be fitted - one to each bedroom rad, fitting a couple of motorized valves and fitting one small radiator to the utility room.

It seems a good fair price especially as the work man is the only one listed in my area as a recommended Worcester Bosch installer on their web site.

I had another local plumber quote me £3900 for almost exactly the same work.

Reply to
RedOnRed

Where is the reg that says a cylinder has to be updated if a new boiler is being installed?

Always go for a quick recovery coil cylinder, part L is false economy. A condesning boiler will greatly benefit from this giving beter economy. Also a quick recovery cylinder is be downsized. Always have a DHW priority system and a two stats on the cylidner to eliminate boiler cycling and give one long efficient burn when re-heating. This is well worth it.

Wate of time as they don't last. Best get Danfoss from

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Pipework and fittings 200 gbp

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Reply to
Doctor Evil

"Paul Barker" wrote | ... I'll be fitting a regular condensing boiler open | vent with open vent dhwc this week as a new installation, | because it is a holliday flat so the frequent changes of | user don't have to be educated about filling loops.

I don't see why weekly or fortnightly tenants should need education about filling loops. Pressurised systems should not need repressurising unless there is something wrong like a leak or pressure vessel failure.

| Open vent systems though hasstle for the installer | (particulalry if he designs his pipe runs badly) are | more user friendly.

One particular reason for a pressurised system in your application, where the property is, I surmise, likely to be unoccupied for periods of time, is that if there is a leak the amount of water in a pressurised system is finite. If a vented system leaks there is an unlimited amount of water to cause damage because the system is continually replenished from the header tank.

Owain

Reply to
Owain

Not really a problem with a modulating boiler since it simply reduces its power output to mathc the reducing load, hence it maintains operation in an efficent temperature range.

Therea are rules for how close the flue can be to windows etc, but these are not that onerrous in most cases. 7" is good since it will be over (most) peoples heads. It also does not want to be directed at a neighbouring property if it is too close.

Culled from an Ideal install guide:

Terminal Position Minimum Spacing

  1. Directly below or alongside an opening window, air brick or other ventilation opening 300 mm (12")
  2. Below guttering, drain pipes or soil pipes 25 mm ( 1")
  3. Below eaves 25 mm ( 1")
  4. Below balconies or a car port roof 25 mm ( 1")
  5. From vertical drain pipes or soil pipes 25 mm ( 1")
  6. From an internal or external corner or to a boundary along side the terminal. 25 mm ( 1")
  7. Above adjacent ground, roof or balcony level 300 mm (12")
  8. From a surface or a boundary facing the terminal 600 mm (24")
  9. From a terminal facing a terminal 1200 mm (48")
  10. From an opening in a car port (e.g. door or window) into dwelling 1200 mm (48")
  11. Vertically from a terminal on the same wall 1500 mm (60")
  12. Horizontally from a terminal on the wall 300 mm (12")
Reply to
John Rumm

If this really is a problem, you could fit a stopcock to the header tank feed - under normal circumstances there will be enough water in the header tank for a couple of years - if not more.

Reply to
Dave Plowman (News)

It is a problem. You need a by-pass valve which raises the return temperature which reduces efficiency. You can get around this by isntalling a flow switch abd timer. By-pass valves should not be on condesning boilers

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Reply to
Doctor Evil

It is better to not fit a TRV on the rad that shares a room with the stat, then you solve the problem without extra switches and timers.

Reply to
John Rumm

Oh my God, look what this fool is saying. Only on the Internet.

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Reply to
Doctor Evil

This is the problem of the internet. Too much advice and some of it not sound.

Anyway, I have taken on board all your comments and at least I have a better idea now.

One final thing. Do you reckon that condensing boiler prices will drop after April or because they will not have any competition, will the prices rise?

Reply to
squidk

Based on a conversation on Saturday with a trade supplier of tiles[1], nothing will happen, because he (like many people) had never heard of Part L in any shape or form and many think building regs are for when you build an extension or knock 2 rooms into 1 (if you're lucky).

Tim

[1] And there's no reason a tile supplier would know, except supplying tradespeople all day, one might have assumed he'd hear more than your average man on the street.
Reply to
Tim S

Servowarm fitted header tanks with no cold water feed at all - you simply topped it up as needed with a bucket. Every couple of years.

Of course, some would say they did this to save the cost of installing a cold water feed. They said it was so that any leaks whould be restricted to the contents of the system. So fitting a feed with a stopcock would give the same claimed 'benefits' without the bother of carrying water to the header tank.

I'm surprised that you - as claimed heating engineer - didn't know this?

But then you only 'know' what you read in advertising blurb. Those of us who live on this planet analyse any new developments to see if they offer any real benefits. Like sealed systems - which are an answer where a header tank can't be installed - as in some flats etc. But not a paragon of reliability judging by the number of posts here about their problems.

Reply to
Dave Plowman (News)

I am lead to believe that you can only fit a conventional boiler after April in exceptional circumstances. This means that they will not be manufactured in large numbers anymore I presume.

So, if I hired a corgi fitter to install the boiler would he have to insist I followed Part L etc for the cylinder or would he turn a blind eye?

I was hoping to convert my system to fully pumped and put in new controls myself so that when I but the boiler, all the guy has to do is fit it.

Reply to
squidk

Why would the prices need to go down? They're most likely to go up once no-one's got any other option and they've got us over a barrel.

Surely the industry's not that cynical though...lol.

Reply to
RedOnRed

The "exceptional circumstances" don't seem very exceptional to me. There's a points scoring system by which qualification of exception can be measured (google back on this group, I think there were some recent references).

With regard to a back boiler my father has, it would a) need to be resited, b) need a condensate pump, c) detached house on natural gas, so he's pretty much home, dry and excepted forever.

Find a friendly fitter who can "help" you through the form. From what I've seen, the rules are relatively vague so they don't need to twisted so much as gently offset from the straight.

Tim

Reply to
Tim S

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