Sputtering hot water tap

[SADavids]

Hi,
I couldn't find anything relating to a sputtering hot water tap, thought I'd start a new topic for advice.

From what I can understand it's probably air in the hot water tank. I live in a flat on the third floor (not sure how relevant that is!), about a week or two ago the bathroom sink hot water tap started to sputter momentarily when turned on, recently it got worse and apparently this is something I can fix myself according to various websites.

One I'm told to block my mixer tap in the bathroom sink (with my palm!) and turn on the hot water, followed by the cold water for 30 seconds. Forcing it the pressure back? I don't fully understand the mechanism behind it but thought I'd check it with some experts before I go ahead!

Another one involves my washing machine but it's quite difficult to access the back as it's built-in. I can move it I suppose but prefer to see what options I have.

I only have two double lever mixer taps and the bath tub one is single lever.

Any pointers greatly appreciated thanks!


S.D.

 

[Madrab]

You don't say what type of hot water/heating you have?

You say you have a hot water cylinder? Where is this fed from, you have a cold water cistern too I take it ?

Does the cold water do it too?

 

[SADavids]

Hi,
thanks for the response. My cylinder is a:

OSO Hotwater, Direct Unvented Water Heater. Not quite a boiler (I don't think?) as my flat has storage heating.

The sputtering only occurs with the hot water tap, cold is fine.

Not entirely sure what a cold water cistern is but I presume in a flat it's just the pipes from a communal one?

I've been living here for four years (bought the apartment) and never had any issues although I think I probably should have the cylinder inspected? I don't know what the regulations are regarding this.

Thanks!!!

 

[Madrab]

OK, you have a mains fed, HW water cylinder heated by electric immersion heaters.
I can't see it being an issue with the WM nor would it likely to be an airlock, that would require you to do the mixer tap trick.
You need to get a qualified un-vented HW engineer in to check it and give it a service. Once a year it is recommended to be looked at. It's not a regulation, yet, but it would be advisable to get it checked and they can look at the spluttering for you.

 

[SADavids]

Actually I managed to find a sticker on the side of the cylinder, there's a number I can ring. Hmmm yeh, maybe I need to have it serviced. I thought if it's a minor problem I can fix it myself but it's been a while since anyone looked at the thing - it's wise to have it looked at.


Does anyone know how much they tend to cost?


Thanks

 

[Madrab]

Like everything it's usually location dependent but I'd be expecting to pay from say between £50 - £70 with safety cert.

 

[ScottishGasMan]

Wont be an airlock in an unvented system, but might be worth remaking the airbubble in the cylinder first if it has one, normaly there would be instruction on the side of it,

or look at page 4 here
http://www.osohotwater.co.uk/images/pdf/domestic/manuals/20-series-installation-manual.pdf

Might not be the same cylinder, but if it does not use an expansion vessel and uses an airbuble, then this is usually a task that can be completed by the end user.

Although its always worth noting, that these type of hot water heaters should be inspected periodically by someone with an unvented qualification to check for safe working

 

[SADavids]

Yeh, I've sent an email directly to OSO Hotwater, hopefully they can send someone around. Alternatively I might ask the building management if anyone else has the same problem and what they did to fix it.

I have no instructions, no installation details and I don't think they even make my model anymore. I did find a tiny sticker the size of a thumb:

Type: OSO DIRECT 170
Capacity: 170 Ltr at 3 bar
Weight full: 243 KG
Heater: 3.0kW/240V/1PH
Prod. no/date: 8598/00/03

I presume this is the 17 series off their official download page - there's nothing helpful on their PDF either.

I'm not entirely sure what the problem might be if it isn't airlock.


Better be safe than sorry, I'm going to need an engineer! £70 ish sounds reasonable.

Thanks for the feedback!

 

[Madrab]

You'll know as you'll be able to match the cylinder you have with the picture in the MI.

You should have the commissioning docs and manual, or at least it would have been left with the owner at the time of installation.

Not sure if OSO themselves will be any more expensive, as independents tend to be a bit cheaper.

The air could be a couple of things, sounds like it's being caught overnight when the tank's not being used. Turbulence can force air out of the water, so can heating if there's anything on the elements (scale etc) though it may be something you have to live with as tracing the cause may become expensive.

 

[SADavids]

I'll see if I can match it tonight, but I'm not that convinced by pictures anyway.

Sadly I have nothing on the cylinder, I reckon the apartment was 10 years old when I bought it. No manual, docs, installation papers - zilch.

Apparently OSO will respond in 24hrs, still waiting


Tracing a piping problem in an apartment block will be an issue!