New combi boiler recommendations for rads and WUFH

[dazzler9000]

Hi all, I'm currently having some issues with my boiler 'Vaillant ecoTec plus 837', where I'm getting random F28/29 and F54 errors. It's pretty old and I'm wondering if it's worth just swapping it out. I'd like the peace of mind of a long warranty etc.

The current system consists of 7 radiators upstairs and wet underfloor heating downstairs. The house is poorly insulated, even the UFH.

Are there any recommendations for boilers, I'll obviously consult a local company for ideas, but would be good to be armed with some info?

I'm sure I was told previously that Vaillant's don't modulate very well? I've noticed that when I have the UFH running, the boiler seems to just chug away continuously for hours, which seems weird to me considering the UFH doesn't need scolding hot water. Sure I also heard the Vaillants don't support opentherm?

I'm no expert, so my comments above could be out of date or just wrong, so hoping for some guidance.

 

[BlueLoo]

Hi all, I'm currently having some issues with my boiler 'Vaillant ecoTec plus 837', where I'm getting random F28/29 and F54 errors. It's pretty old and I'm wondering if it's worth just swapping it out. I'd like the peace of mind of a long warranty etc.

The current system consists of 7 radiators upstairs and wet underfloor heating downstairs. The house is poorly insulated, even the UFH.

Are there any recommendations for boilers, I'll obviously consult a local company for ideas, but would be good to be armed with some info?

I'm sure I was told previously that Vaillant's don't modulate very well? I've noticed that when I have the UFH running, the boiler seems to just chug away continuously for hours, which seems weird to me considering the UFH doesn't need scolding hot water. Sure I also heard the Vaillants don't support opentherm?

I'm no expert, so my comments above could be out of date or just wrong, so hoping for some guidance.

Don't throw good money after bad.
Your gung-ho attitude will have the plumbing vultures licking their lips.


You complaining about boiler running and also say your insulation is poor. The two are not unrelated.

Don't just get a boiler chucker in.
Get the system reviewed and done correctly.

Get quotes and show the trades here.

 

[Mike13]

F28 and F29 are ignition and gas side errors. Also while looking at the replacement ideas you should look at the sizes and condition of your radiators. UFH needs a separate mixer to keep the temperature lower than is the case for radiators.
Like BL says, look at the insulation of your property, that means things dont have to work so hard.
Is the UFH having decent insulation underneath it? often it is put in without considering the extra wasted heat going into the ground underneath.
Sitting room floor at 20C, ground underneath at say 10 degrees, then you fit UFH with water at 35 C, ground still at 10C, you have now added 50 % to the heat leak through the floor compared to before, if it is circulating at 40 you have doubled the heat leak under those rooms.

 

[muggles]

As Mike says, those faults are related to gas supply issues. It could be a problem with the regulator on your meter, or could be a problem with the gas valve or circuit board in the boiler. Any of these will be cheaper to fix than buying a new boiler. Your boiler doesn't modulate very well (new Vaillants do, however) but you'll never ever recoup the cost of replacing it in gas savings even if the new one is perfectly set up.

 

[dazzler9000]

Thanks for the advice so far. I have few threads on this forum, but basically, I have uncovered a few issues since moving into this house four years ago.

I've found that my underfloor heating installation sits on top of uninsulated floor boards which face a suspended floor (outside), so I'm throwing money away there, I need to rip up my oak flooring for the entire ground floor and insulate between the joists, then replace flooring and UFH (can't get under the house to insulate), the Mrs doesn't like that idea and I can't blame her. I may do away with the UFH as it's never really done a lot, no doubt not helped by the installation/insulation.

My house has some single-skinned walls, which need external wall installation and I suspect I may have some subsidence that needs investigating after I remortgage next year. So plenty to do and not much funds to do it.

As of now, my boiler is erroring every couple of days, and bearing in mind its age (think it's 12-14 years old, I thought a replacement might be more economical than randomly replacing parts one by one. I've been there before with a boiler in my old house and ended up replacing it after chucking £300-400 at it.

My idea was to replace the boiler like for like and connect to the UFH as is. I have a wood burner I can use to supplement the heat from the poor-performing UFH.

 

[dazzler9000]

As Mike says, those faults are related to gas supply issues. It could be a problem with the regulator on your meter, or could be a problem with the gas valve or circuit board in the boiler. Any of these will be cheaper to fix than buying a new boiler. Your boiler doesn't modulate very well (new Vaillants do, however) but you'll never ever recoup the cost of replacing it in gas savings even if the new one is perfectly set up.

I've checked the gas supply valve and it's not been partially switched off (it's in a box outside) and the emergency gas engineer checked the flow, apparently that's okay? Hadn't thought that it could be a supply issue instead of a boiler issue.

I'd read that the gas valve could be the issue or CB, just don't want to take punts on an old boiler, unless the engineer is certain. The other issue is that I spend money on fixing it and then something else breaks.

 

[muggles]

The modern equivalent 840 has better modulation but is knocking on the door of £2000 by the time you've bought the boiler and flue. To get best efficiency out of it you really also need the sensoHOME controller, about another £200, and of course materials and labour to get it installed. Or Vaillant will repair what you have for a fixed price, and give you a 12 month warranty, assuming it is a boiler fault and not a supply fault

 

[dazzler9000]

The modern equivalent 840 has better modulation but is knocking on the door of £2000 by the time you've bought the boiler and flue. To get best efficiency out of it you really also need the sensoHOME controller, about another £200, and of course materials and labour to get it installed. Or Vaillant will repair what you have for a fixed price, and give you a 12 month warranty, assuming it is a boiler fault and not a supply fault

I hadn't thought about calling Vaillant directly. Guess they'd have the best chance of fixing it first time. I'll give them a call tomorrow and get a quote. Would this be the best advice over calling out an independent?

 

[muggles]

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[BlueLoo]

UFH on a suspended floor?

Hmmm.

Is that possible without some serious sub floor insulation engineering?

 

[dazzler9000]

UFH on a suspended floor?

Hmmm.

Is that possible without some serious sub floor insulation engineering?

Well I definitely have a hole under my house, I know that much. Here's my thread on the topic

Spray foam underfloor insulation

Hi all, I've recently come to the conclusion, that my inherited wet underfloor heating is more than likely sat on cement boards, then floorboards which face the outdoor open suspended floor cavity. I still need to find a section to investigate and confirm, but I have a hunch that there is no...

www.diynot.com

 

[dazzler9000]

I had a chat with a friend today who lives on my road, he was in the process of getting his driveway dug up as he has a low-pressure gas supply. Apparently, there are a few on my road that have had the same issue.

I've always suspected my boiler, but what are the chances that my issue could be a supply issue? What's the process for investigating this, do I need to pay a heating engineer to test the supply into the house?

 

[muggles]

Ask your gas transporter to carry out a GT1 survey

 

[dazzler9000]

Rookie question. Do I call my provider, i.e. octopus and they will contact the the gas board? Will they attend without proof form a heating engineer?

 

[muggles]

No, you need to contact your transporter. It'll be either SGN, Northern Gas, Cadent, or Wales & West