Utility room cold after bolier replacement

[SPuJ]

I have just had my ancient Potterton Neataheat boiler replaced with a Vaillant 428. The boiler is in a small utility room that we mainly use for hanging clothes to dry. The old Potterton used to throw out a fair bit of heat from the casing but the new boiler gives virtually no heat to the room. Consequently the clothes aren't drying! The room has no space for a radiator (or tumble dryer for that matter).

The boiler is on the ground floor with long 28mm pipe runs to the cupboard on the landing which contains the pump two zone valves and the DHW cyclinder.

I do have room for a kick space convector but that would require some piping along the walls in the adjacent room since I don't really fancy digging up the concrete floors.

So, I'm considering a second option which I would like your opinion on. I could put a high level convector heater (Myson Hi Line or similar) on the same wall as the boiler. There is no possibility to get at the CH flow (after its zone valve) at this point so I'm wondering about putting the convector across a section of the boiler return pipe in a one-pipe system fashion. This would give the added advantage of clothes drying when just the DHW is on. If necessary I could make an injection tee with 28mm tee and 28-22 reducer (as discussed elsewhere on this forum) on the return side of the convector to force water through it.

One downside of this is that that return temperature is fairly cool (probably averaging 50 degrees at the moment) because I am running a VRC 430 weather compensator. Having said that temperatures are higher when the DHW cylinder is calling for heat and will get higher as the outside temperature falls.

So, given that I'd have to oversize the convector becuase of the low temps, would this work?

Thanks for any thoughts

 

[adlplumbing]

you could use towel rads
they would be able hang our clothes on these as well for drying

 

[SPuJ]

That's a neat idea adlplumbing, thanks.

The main issue remains how I can plumb in any kind of radiator. Would two connections into the boiler return with maybe an injector tee on the rad return side be OK?

 

[adlplumbing]

i am going to suggest you get some one in
or take lot`s photo and post them

p.s. their thank you button

 

[shagty]

hi there

i think a natural convector unit fitted at low level would provide the optimum solution.

convectors transmit more heat per litre of water than towel rails so a compact unit should meeting your heating needs. however natural convectors must be fitted at low level to enable effective heat transmission. if you are confined to high level then it must be fan assisted to overcome buoyancy.

convectors work well on low temperature circuits but a smaller unit could be used if you could break into the HWS line. hooking it up in parallel with the cylinder would mean you could provide timperature control with a TRV as well.

i fitted a model in my parents airing cupboard and it works well (for airing though). I think it was a Licon floor standing unit and measured about 350L * 200W * 250H. (similar to the unit in the image below). you could also consider slim line skirting heaters if wall or floor units dont work.

a natural vent at high level would be important if your boiler is room-sealed and you plan to dry damp clothes.

hope this helps

nat convector

• shagty
• 16 Nov 2011
• 1

 

[Biggles..]

I think messing about adding resistance to the common return pipework with injector tees on a 400 series Vaillant especially the bigger ones is asking for trouble.

 

[SPuJ]

Thanks all for your helpful suggestions.

shagty - the natural convector would be a good idea but unfortunately I don't have the floor space for it. The HWS line is in the landing cupboard over the other side of the house. To connect there would involve messing with a lot of fitted carpets and chipboard floors. Whilst I'm not adverse to doing that I was hoping for a less disruptive solution. Good point about the high level vent - I'll put one in when I get a chance.

LeeC - I do take your point about restrictions in the boiler return. However, this is a 28mm pipe which used to go to the old boiler. It is reduced to 22mm anyway before it goes into the new boiler so a 22mm restriction in the 28mm pipe form an injector tee wouldn't make much difference would it?

 

[Boilerman2]

Why not fit an ELECTRIC kickspace i.e. not a Hydralic type
if getting pipes to the unit are a pain, and electric version only needs a 13a supply - probalby your easy answer!

 

[namsag]

And yous think this is a real post , guy is talking in a way that is not diy but he is surprised that a new boiler does not give heat into the room ? ? ?

 

[SPuJ]

Thanks Boilerman2. Maybe an electric kickspace would be an easier way to go. Seems a shame given the proximity of the hot water though. Not sure how running costs would compare these days.

namsag - I did realize this would be an issue but the boiler had to be replaced so now I'm just looking for the most practical way to get some heat back in there. I'm a DIYer and have done my own plumbing for many years though, of course, I had to have the boiler itself fitted by a gas safe engineer.

 

[shagty]

I was under the impression the HWS cylinder was next door.
as its not, there is merit in tapping into the primary flow & return with two 15mm lines and a penny valve on each side for isolation and balancing.

Fitting the proposed new heater in parallel instead of a series connection is much wiser IMO. Injector tees are not cheap and flow would be impeded somewhat as the previous poster points out.

hydronic kick-board heaters (fan assisted) are available but I believe are quite expensive. i have a natural convector (fin and tube section removed from a trench heater) under my kitchen units where a kick board heater would go and it works well. alternatively, slim line skirting heaters are very compact.

a caveat regarding room air quality and ventilation. you may need to provide mechanical ventilation as the new boiler may contain a electronic control module and would be more sensitive to moisture than the old unit. you could consider a fan with an integrated humidity sensor such as the vent-axia range. the potential for surface and interstitial condensation could also be removed with a fan.

 

[SPuJ]

Thanks again shagty. Unfortunately the pump is up in the landing cupboard too so it rules out going across the boiler flow and return.

Having looked at the pipework again today and taking into consideration the comments here about restrictions etc. I've deiced not to go that route. I think I will compromise and go for a Myson Kick-space 500 Duo. This will run off the heating circuit but also has a 1Kw electrical heater which we can use when the CH is not on. I'll have to live with pipes along the wall of the adjacent room but maybe it's not such a big deal.

Thanks everyone for your helpful suggestions.