does a Combi boiler need a strainer/filter at inlet?

[rizsher]

Hi,

I got my boiler replaced recently (after lots of advise and help from folks at the forums here), and the system worked brilliantly for 3 weeks (its a Viessmann 200w combi boiler). Day before yesterday, the proverbial seemed to have happened, and the CH stopped working, DHW was fine, but, no heating in the house.

Managed to get a Viessmann engineer out quite quickly who was able to fix it in no time. The problem was traced to a pebble, about 3 mm in size that had gotten stuck in the diverter/pump wet switch preventing the boiler from switching from hot water to central heating duty.

After the service engineer left, I called the Viessmann support line and inquired if the boiler had a built-in filter/strainer to prevent foreign matter from entering the boiler. They said, the boiler has no such thing, but my mains should have a filter.

I then called the installation company and asked if this was something they had overlook, or, if a strainer SHOULD be installed. They said nothign like this is needed or required.

Given I've already had 1 3mm asteroid coming in from somwhere, is a strainer/filter recommended to be installed on combi boilers?... or I should just accept that pebble to be 1 off and hope nothing ever happens again?.

 

[mickyg]

its not a requirement but it wouldn't hurt. tbh your problem sounds like something very rare. Unless the Viessmann engineer made any suggestions then I wouldn't worry about it.

 

[martyheat]

[hi it can happen but rear
good practice to fit scalmaster a 1m from unit on cold mains.
good choice of boiler.javascript:emoticon('')

 

[AkuraEngineer]

if thames water or who ever it is they contract now a days have done any work in the road or repaired any mains water pipes in the road it is comon to see earth coming out of your tap as they almost always tend to get dirt in the water mains and if your boiler has a filter (such as warcester boiler 24is etc) they can get easily blocked up reducing the water flow rate

maybe someone somewhere has worked in the street and is the reason as to why you had strange objects in your water suply other than that you shouldnt be getting foreign bodies in your boiler

also another thing to take into consideration is if your do not have a non return valve fitted it is possible for the central heating water to mix with the incoming mains water but saying that, that should cuase this problem at hand

 

[Agile]

if thames water or who ever it is they contract now a days have done any work in the road or repaired any mains water pipes in the road it is comon to see earth coming out of your tap as they almost always tend to get dirt in the water mains and if your boiler has a filter (such as warcester boiler 24is etc) they can get easily blocked up reducing the water flow rate

Do Thames Water really work in Aberdeen?

 

[AkuraEngineer]

if thames water or who ever it is they contract now a days have done any work in the road or repaired any mains water pipes in the road it is comon to see earth coming out of your tap as they almost always tend to get dirt in the water mains and if your boiler has a filter (such as warcester boiler 24is etc) they can get easily blocked up reducing the water flow rate

Do Thames Water really work in Aberdeen?

i was just using thames water as an example i have no idea who supplies the water in aberdeen

 

[Agile]

Scottish Water would sound more plausible!

 

[AkuraEngineer]

double post

 

[AkuraEngineer]

Scottish Water would sound more plausible!

im genuinly happy for you, youve answered your own question as i had no concern in who it is, who it was or who it might be, i still remain confident in the knowledge that rizsher would relate who i refere to as my water supplier to his own not exactly the big issue here

 

[rizsher]

Thanks for the response guys. Can anyone recommend a decent strainer, ideally with some sort of easy-clean arrangement that I would be able to clean every now and then without too much hassle?.

I asked my plumber and he said he'll look inthe catalogue and get back to me.

Regards.
Riz

 

[rizsher]

So, I finally got a 15mm strainer from the local plumb center and got it installed at the inlet 1m water supply to my combi boiler (it is installed upstream of the CH Pressuirsation loop.

Have noticed a significant drop in shower quality; pressure isn't as good as it used to be.

I had noticed the mesh in the strainer was quite fine, I would guess about 1 mm holes. Is it possible to get replacement mesh sizes with slighly bigger sieve sizes?. Where would I get these from?.

Riz

 

[Agile]

Fitting a gauze filter on the mains water supply will do no harm and might even be useful if Scottish water should dig the streets and get dirt into the supply.

However, the problem on your boiler was nothing to do with the mains water.

The pebble came from your heating system!

The reality is that it probably arose because the installer cut the pipes under the boiler position and did not cover the pipes and allowed drilling debris to fall into the pipes.

The warrantee engineer should have charged for the callout as it was not the manufacturer's dirt.

I am very pleased to hear that, just as I have found myself, the Viessmann service agents come quickly and are able to find the faults quickly.

Tony

 

[rizsher]

Well...

Don't really know system in enough detail exactly HOW the line out is; however, I believe the pebble came from the mains water as it had gotten stuck in the floating switch in line with the mains water feed to the boiler.

The Viessmann Engineer took a bit of convincing; TBH, the customer support rep I talked to was quite rude, rude enough for me to email their Customer service department (another story, two weeks later, I got a call from a manager who said they'll be responding to me in writing shortly, and that she was just calling to confirm that my complaint had been received - this was back in February; still waiting for the reply!!!). Anyway, I couldn't help getting fobbed off by this particular CSR I kept getting connected to; so I called, asked for a supervisor, and was told the super is away on holiday, so I said, well get me anyone besides yourself, was told to hold on, and promptly disconnected. After this I had gone online, filled the complaint form; by this time it was 5:30 and the support line had gone to 60s music interrupted by a recording telling me to call back the next day)... Anyways, next day I called, was todl their enginers are busy, and I said the damn boiler is 3 weeks old, you had better get someone to look at it TODAY. To their credit; they actually arranged for a third party boiler engineer to come and look at it. and it was fixed the day after it had stopped working.

Whether they should've charged for it; I don't know; one would expect a boiler which is being fed from the mains to have some sort of filtration at the inlet; just makes good design sense. If they've not got it; as far as I'm concerned, they gotta fix.

Right, after all this; the query I had was, I've ALREADY installed a strainer. but the mesh is quite fine, leading to drop in water pressure. Is it possible to get a mesh basket for these Y strainers with bigger holes?. Failing that, I'll be tempted to punch some bigger holes in the mesh myself.

 

[Agile]

Hi,

Managed to get a Viessmann engineer out quite quickly who was able to fix it in no time. The problem was traced to a pebble, about 3 mm in size that had gotten stuck in the diverter/pump wet switch preventing the boiler from switching from hot water to central heating duty.

Your original posting seemed to be saying that the pebble was in the diverter valve which is system water!

If in fact it was in the DHW demand switch then a strainer on the cold feed will prevent that problem as expected.

Tony

 

[rizsher]

Agile,

Thanks for the response. You do realise I have a strainer fitted now; my query is quite different to the original one.

Riz